论文标题
单晶钨中纳米引导的原子模拟：原子间电位的作用
Atomistic simulations of nanoindentation in single crystalline tungsten: The role of interatomic potentials
论文作者
论文摘要
计算建模通常用于帮助对先进材料的实验探索，以更好地了解机械测试期间的基本可塑性机制。在这项工作中，我们执行分子动力学（MD）模拟，通过不同的原子质电位模仿晶体W矩阵的实验室温球形 - 纳米识别：EAM，Modified EAM和最近基于机器的基于机器基于的列表的高斯高斯高斯近似电势（TABGAP），以描述W-W的相互作用。结果表明，无论数值模型如何，负载位移与应力 - 应变曲线之间的相似性。然而，在弹性到塑性变形过渡的早期阶段观察到差异，显示出不同的脱位成核和进化的机制，这归因于汉堡矢量幅度的差异，堆叠断层和脱位滑行能。此外，通过考虑大缩进尺寸的大小来研究接触压力，该大小在加载过程中对螺钉和边缘位错方面进行详细分析。此外，报告了所有原子间电位的这种位错的滑行屏障，表明TABGAP模型在密度功能理论计算方面呈现了最准确的结果，并且与报告的实验数据呈现了良好的定性一致性
Computational modeling is usually applied to aid experimental exploration of advanced materials to better understand the fundamental plasticity mechanisms during mechanical testing. In this work, we perform Molecular dynamics (MD) simulations to emulate experimental room temperature spherical-nanoindentation of crystalline W matrices by different interatomic potentials: EAM, modified EAM, and a recently developed machine learned based tabulated Gaussian approximation potential (tabGAP) for describing the interaction of W-W. Results show similarities between load displacements and stress-strain curves, regardless of the numerical model. However, a discrepancy is observed at early stages of the elastic to plastic deformation transition showing different mechanisms for dislocation nucleation and evolution, that is attributed to the difference of Burgers vector magnitudes, stacking fault and dislocation glide energies. Besides, contact pressure is investigated by considering large indenters sizes that provides a detailed analysis of screw and edge dislocations during loading process. Furthermore, the glide barrier of this kind of dislocations are reported for all the interatomic potentials showing that tabGAP model presents the most accurate results with respect to density functional theory calculations and a good qualitative agreement with reported experimental data
