Title: A phenomenological dislocation mobility law for bcc metals Show Chinese title

Title: 体心立方金属的表观位错迁移率定律

Abstract: Dislocation motion in body centered cubic (bcc) metals displays a number of specific features that result in a strong temperature dependence of the flow stress, and in shear deformation asymmetries relative to the loading direction as well as crystal orientation. Here we develop a generalized dislocation mobility law in bcc metals, and demonstrate its use in discrete Dislocation Dynamics (DD) simulations of plastic flow in tungsten (W) micro pillars. We present the theoretical background for dislocation mobility as a motivating basis for the developed law. Analytical theory, molecular dynamics (MD) simulations, and experimental data are used to construct a general phenomenological description. The usefulness of the mobility law is demonstrated through its application to modeling the plastic deformation of W micro pillars. The model is consistent with experimental observations of temperature and orientation dependence of the flow stress and the corresponding dislocation microstructure. Show Chinese abstract

Abstract: 体心立方(bcc)金属中的位错运动表现出一些特定特征，导致流动应力具有强烈的温度依赖性，并且在剪切变形中相对于加载方向以及晶体取向表现出不对称性。 在这里，我们开发了一种适用于bcc金属的广义位错迁移率定律，并展示了其在钨(W)微柱塑性流动的离散位错动力学(DD)模拟中的应用。 我们介绍了位错迁移率的理论背景，作为所开发定律的激励基础。 分析理论、分子动力学(MD)模拟和实验数据被用来构建一个一般的现象学描述。 通过将其应用于建模W微柱的塑性变形，展示了迁移率定律的实用性。 该模型与流动应力的温度和取向依赖性以及相应位错微观结构的实验观察结果一致。