第 54 卷第 8 期2023 年 8 月中南大学学报(自然科学版)Journal of Central South University (Science and Technology)V ol.54 No.8Aug. 2023金属镁非共面位错相互作用强度的位错动力学模拟李赛毅1, 2，张磊1，杨继翔1(1. 中南大学 材料科学与工程学院，湖南 长沙，410083；2. 中南大学 有色金属材料科学与工程教育部重点实验室，湖南 长沙，410083)摘要：采用位错动力学方法模拟金属镁在塑性变形过程中的基面、柱面及一阶锥面<a >位错非共面相互作用，利用扩展Taylor 硬化方程计算潜硬化系数，探讨位错相互作用强度及其影响因素。
研究结果表明，位错相互作用强度随滑移机制以及主滑移系与林滑移系的交换而变化，表现出显著的各向异性和非对称性。
共线基面/柱面相互作用最强，非共线柱面/基面相互作用最弱，相应的潜硬化系数分别为0.43和0.11。
共线相互作用下主位错长度由于位错湮灭明显比非共线相互作用下的小，非共线作用下则形成大量位错交结或交叉态位错。
虽然共线相互作用总体上略强于非共线作用，但特定主位错−林位错相互作用对的共线与非共线作用相对强弱随非共线作用下形成的交结性质而变化。
当非共线相互作用形成固着交结或交叉态时，非共线作用强度高于共线作用强度，而当形成的交结为可动交结时则弱于共线作用强度。
充分考虑位错可动性及摩擦阻力的差异是有效预测位错相互作用强度及其各向异性的重要前提。
关键词：位错动力学；潜硬化；交结；滑移；位错相互作用中图分类号：TG113.25 文献标志码：A 文章编号：1672-7207（2023）08-3048-10Dislocation dynamics simulations of non-coplanar dislocationinteraction strengths in magnesiumLI Saiyi 1, 2, ZHANG Lei 1, YANG Jixiang 1(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central SouthUniversity, Changsha 410083, China)Abstract: Non-coplanar interactions between basal, prismatic and first-order pyramidal <a > dislocations in magnesium were investigated using dislocation dynamics simulations. The resulting shear stresses were applied to calculate latent hardening coefficients using an extended Taylor hardening law. The differences in strengths of收稿日期： 2022 −04 −11； 修回日期： 2022 −05 −20基金项目(Foundation item)：国家自然科学基金资助项目(51271204，51571213)；中南大学高性能计算公共平台项目(2021)(Projects(51271204, 51571213) supported by the National Natural Science Foundation of China; Project(2021) supported by the High Performance Computing Center of Central South University)通信作者：李赛毅，博士，教授，从事金属塑性变形与织构的研究；E-mail ：*************.cnDOI: 10.11817/j.issn.1672-7207.2023.08.009引用格式： 李赛毅, 张磊, 杨继翔. 金属镁非共面位错相互作用强度的位错动力学模拟[J]. 中南大学学报(自然科学版), 2023, 54(8): 3048−3057.Citation: LI Saiyi, ZHANG Lei, YANG Jixiang. Dislocation dynamics simulations of non-coplanar dislocation interaction strengths in magnesium[J]. Journal of Central South University(Science and Technology), 2023, 54(8): 3048−3057.第 8 期李赛毅，等：金属镁非共面位错相互作用强度的位错动力学模拟various dislocation interactions were evaluated based on the computed latent hardening coefficients and then discussed by examining dislocation configurations developed during deformation. The results show that the interaction strength varies with the involved slip systems and with the exchange of primary and forest systems, indicating strong anisotropic and asymmetric latent hardening. The highest strength is found for collinear basal/ prismatic interaction and the lowest for non-collinear prismatic/basal interaction, with a latent hardening coefficient of 0.43 and 0.11, respectively. The primary dislocations developed in collinear interactions are generally shorter than those in non-collinear interactions due to dislocation annihilation, while a large amount of dislocation junctions or crossed states are formed in the latter ones. The strength of collinear interactions is in average moderately higher than that of non-collinear interactions. However, for a given pair of primary and forest systems, collinear interaction is stronger than non-collinear interaction when the junctions formed in non-collinear interaction are glissile, and the reverse is true when sessile junctions or crossed states are developed in non-collinear interaction. These results reveal a strong dependency of the relative strength between collinear and non-collinear interactions on junction properties, which is different from fcc and bcc crystals. Differences in mobility and friction stress between interacting dislocations need to be taken into account for a faithful prediction of the interaction strengths and their anisotropy.Key words: dislocation dynamics; latent hardening; junction; slip; dislocation interaction金属材料的应变硬化除了位错滑移导致的自硬化之外，还存在不同滑移系位错相互作用所引起的潜硬化。
