Supporting Material for Improved Quantitative Phase-Field Approach for Simulating Grain Coarsening in Anisotropic Systems with Arbitrary Inclination and Misorientation Dependence

Simulation programs, input files, results and supplementary data related to the paper "New phase-field model for polycrystalline systems with anisotropic grain boundary properties", N. Moelans, Materials & Design, 217, 110592. Paper Abstract : In the papers [PRL 101, 025502(2008); PRB 78, 024113 (2008)], the author proposed a quantitative phase-field model to study grain growth in polycrystalline structures with misorientation and inclinatin dependence of the grain boundary properties. In later studies, it was found that the model can show some issues when for strong anisotropies. In this paper, an improved model, resolving these issues, is presented. The new approach is derived in a fully variational way, while unphysical third phase contributions at grain boundaries are suppressed without the need of extra higher order terms. The new model contains a parameter to control the length scale of the diffuse interface without affecting the grain boundary properties for computational efficiency. It is verified for the new approach that accurate triple junction angles are obtained under all conditions, also for large differences between the grain boundary energies resulting in triple junction angles that deviate largely from 120$^{\circ}$. It is also shown that grain boundary wetting is reproduced. Moreover, three alternative ways to include inclination dependence in the model are presented and validated, resulting in a founded selection of one of them. The applicability and accuracy of phase-field models towards systems with strong anisotropy is largely increased with the newly proposed methodology.

与论文"New phase-field model for polycrystalline systems with anisotropic grain boundary properties"（作者N. Moelans，发表于《材料与设计》217卷，论文编号110592）相关的模拟程序、输入文件、计算结果及补充数据。论文摘要：在过往研究[《物理评论快报》(Physical Review Letters, PRL) 101, 025502(2008); 《物理评论B》(Physical Review B, PRB) 78, 024113(2008)]中，作者提出了一款定量相场模型（quantitative phase-field model），用于研究具有晶界特性取向差与倾斜度依赖性的多晶结构中的晶粒长大行为。后续研究发现，当体系存在强各向异性时，该模型会出现若干缺陷。本文提出了一款可解决上述问题的改进型相场模型。新方法采用完全变分法推导得到，可在无需引入额外高阶项的前提下，抑制晶界处产生的非物理第三相贡献。新模型包含一个可调控扩散界面特征长度的参数，且该参数不会为提升计算效率而改变晶界固有特性。经验证，新方法可在所有工况下获得准确的三结点角度，即便晶界能差异较大导致三结点角度显著偏离120°时亦是如此。研究同时证实，该模型可复现晶界润湿现象。此外，本文还提出并验证了三种在模型中引入倾斜度依赖性的可选方案，最终确立了其中一种的合理选择。相较于原有方法，新提出的方法论大幅提升了相场模型针对强各向异性体系的适用性与预测精度。