论文标题
晶界处的溶质分离规则
A Rule of Solute Segregation at Grain Boundaries
论文作者
论文摘要
在工程合金特性中，在晶界（GBS）上对溶质分离的控制至关重要，但是关键参数的结构活性关系 - 隔离能量仍然难以捉摸。在这里，我们提出了基于溶质的价，电负性和大小以及自由表面的非本地协调数量的GB隔离的电子和几何描述，而自由表面的非本地协调数，我们通过它们构建一个预测框架，以确定跨不同溶质，矩阵，GB结构和隔离位点的隔离能量。该框架不仅揭示了GB隔离中溶质和矩阵的耦合规则，还揭示了溶质分离确定因素的起源。溶质的贡献本质上是由于合金中的D和S状态耦合，而矩阵GB接口的贡献是由矩阵的无基质表面确定的。我们的计划为GBS的溶质隔离建立了一幅新颖的图片，并为高级合金设计提供了有用的工具。
The control of solute segregation at grain boundaries (GBs) is essential in engineering alloy properties, however the structure-activity relationship of the key parameter-the segregation energies-still remains elusive. Here we propose the electronic and geometric descriptors of GB segregation based on the valence, electronegativity and size of solutes and the non-local coordination number of free surfaces, with which we build a predictive framework to determine the segregation energies across different solutes, matrices, GB structures and segregation sites. This framework uncovers not only the coupling rule of solutes and matrices in GB segregation, but also the origin of solute-segregation determinants. The contribution of solutes essentially stems from their d- and s-state coupling in alloying, whereas that of matrix GB interfaces is determined by matrix free surfaces. Our scheme builds a novel picture for the solute segregation at GBs and provides a useful tool for the design of advanced alloys.
