Salvalaglio Marco, Voigt Axel, Huang Zhi-Feng, Elder Ken R
Institute of Scientific Computing, TU Dresden, 01062 Dresden, Germany.
Dresden Center for Computational Materials Science, TU Dresden, 01062 Dresden, Germany.
Phys Rev Lett. 2021 May 7;126(18):185502. doi: 10.1103/PhysRevLett.126.185502.
The velocity of dislocations is derived analytically to incorporate and predict the intriguing effects induced by the preferential solute segregation and Cottrell atmospheres in both two-dimensional and three-dimensional binary systems of various crystalline symmetries. The corresponding mesoscopic description of defect dynamics is constructed through the amplitude formulation of the phase-field crystal model, which has been shown to accurately capture elasticity and plasticity in a wide variety of systems. Modifications of the Peach-Koehler force as a result of solute concentration variations and compositional stresses are presented, leading to interesting new predictions of defect motion due to effects of Cottrell atmospheres. These include the deflection of dislocation glide paths, the variation of climb speed and direction, and the change or prevention of defect annihilation, all of which play an important role in determining the fundamental behaviors of complex defect network and dynamics. The analytic results are verified by numerical simulations.
通过解析推导位错速度，以纳入并预测在具有各种晶体对称性的二维和三维二元系统中，优先溶质偏析和科垂尔气团所引发的有趣效应。通过相场晶体模型的振幅公式构建了缺陷动力学的相应细观描述，该模型已被证明能在多种系统中准确捕捉弹性和塑性。给出了由于溶质浓度变化和成分应力导致的皮奇 - 科勒力的修正，从而得出了由于科垂尔气团效应而产生的关于缺陷运动的有趣新预测。这些包括位错滑移路径的偏转、攀移速度和方向的变化，以及缺陷湮灭的改变或阻止，所有这些在确定复杂缺陷网络和动力学的基本行为中都起着重要作用。解析结果通过数值模拟得到验证。
