Amirian Benhour, Jafarzadeh Hossein, Abali Bilen Emek, Reali Alessandro, Hogan James David
Department of Mechanical Engineering, University of Alberta, Edmonton, T6G 2R3 AB Canada.
Department of Civil Engineering and Architecture, University of Pavia, I-27100 Pavia, Italy.
Comput Mech. 2022;70(4):803-818. doi: 10.1007/s00466-022-02209-3. Epub 2022 Jul 27.
Crack initiation and propagation as well as abrupt occurrence of twinning are challenging fracture problems where the transient phase-field approach is proven to be useful. Early-stage twinning growth and interactions are in focus herein for a magnesium single crystal at the nanometer length-scale. We demonstrate a basic methodology in order to determine the mobility parameter that steers the kinetics of phase-field propagation. The concept is to use already existing molecular dynamics simulations and analytical solutions in order to set the mobility parameter correctly. In this way, we exercise the model for gaining new insights into growth of twin morphologies, temporally-evolving spatial distribution of the shear stress field in the vicinity of the nanotwin, multi-twin, and twin-defect interactions. Overall, this research addresses gaps in our fundamental understanding of twin growth, while providing motivation for future discoveries in twin evolution and their effect on next-generation material performance and design.
裂纹萌生与扩展以及孪晶的突然出现是具有挑战性的断裂问题，其中瞬态相场方法已被证明是有用的。本文聚焦于纳米长度尺度下镁单晶的早期孪晶生长及相互作用。我们展示了一种基本方法，以确定控制相场传播动力学的迁移率参数。其理念是利用已有的分子动力学模拟和解析解来正确设定迁移率参数。通过这种方式，我们运用该模型来深入了解孪晶形态的生长、纳米孪晶、多孪晶及孪晶缺陷相互作用附近剪切应力场随时间演化的空间分布。总体而言，这项研究填补了我们对孪晶生长基本理解上的空白，同时为未来在孪晶演化及其对下一代材料性能和设计影响方面的发现提供了动力。
