Grain boundary (GB) migration stands as a linchpin process governing microstructural evolution in polycrystalline materials. Over the past decade, the concept of shear coupling, quantified through the shear coupling factor, has transformed our understanding and driven the development of theoretical frameworks for unifying GB behaviors. In this study, we introduced a novel concept of shear coupling strength designed to overcome the limitations of the conventional shear coupling factor, notably its deficiency in conveying "coupling" information. The shear coupling tensor formed by the shear coupling strengths characterizes intrinsic shear coupling properties across diverse GBs and reveals complex dynamics within the GB mobility tensor. The molecular dynamics simulation confirms the symmetry of the GB mobility tensor. This symmetry is inherently built into the shear coupling strength, aligning with an assumption made in previous studies. Additionally, an efficient methodology has been developed for streamlined extraction of both shear coupling and GB mobility tensors from atomistic simulations. This advancement holds the potential to sample GB behavior across extensive datasets, significantly enhancing our ability to predict structure-property relationships within the expansive 5-parameter space of GBs.

中文翻译：

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本征晶界剪切耦合张量


晶界（GB）迁移是控制多晶材料微观结构演化的关键过程。在过去的十年中，通过剪切耦合因子量化的剪切耦合概念改变了我们的理解，并推动了统一GB行为的理论框架的发展。在这项研究中，我们引入了剪切耦合强度的新概念，旨在克服传统剪切耦合因子的局限性，特别是其在传达“耦合”信息方面的缺陷。由剪切耦合强度形成的剪切耦合张量表征了不同GB的固有剪切耦合特性，并揭示了GB迁移率张量内的复杂动力学。分子动力学模拟证实了GB迁移率张量的对称性。这种对称性本质上内置于剪切耦合强度中，与之前研究中的假设一致。此外，还开发了一种有效的方法，用于从原子模拟中简化剪切耦合和 GB 迁移率张量的提取。这一进步有可能在广泛的数据集中对 GB 行为进行采样，从而显着增强我们在 GB 的广阔 5 参数空间内预测结构-性质关系的能力。