Wang Hao, Tian Ji-Ting, Zhou Wei, Chen Xiao-Fei, Bai Bin, Xue Jian-Ming
State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, HEDPS, and IFSA Collaborative Innovation Center of MoE College of Engineering, Peking University Beijing People's Republic of China
Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics Mianyang People's Republic of China
RSC Adv. 2018 Apr 16;8(25):14017-14024. doi: 10.1039/c8ra00141c. eCollection 2018 Apr 11.
The interactions of an edge dislocation (ED) with collision cascades induced by 5 keV primary knocked-on atoms (PKAs) towards the ED in bcc Fe are studied using classical molecular dynamics (MD) simulations. It is found that the number and distribution of the residual point defects are related to the distance between the initial PKAs and the ED. Based on this result, we provide a comprehensive summary of four characteristic phenomena for cascade-ED interactions, including few interactions, the formation of a vacancy cluster, the sink effect for point defects, and the sub-cascade area affection, depending on the overlap of the peak cascades' area with the ED line. Then a qualitative model is proposed to clearly elucidate the underlying mechanisms of the four situations. Considering that dislocations constitute an essential part of the micro-structure of crystalline solids, our work demonstrates that: the pre-existing dislocations in crystalline materials could induce diverse effects under irradiation environments, which should be taken into account for designing and improving the radiation resistant materials.
采用经典分子动力学（MD）模拟研究了体心立方铁中5 keV初级撞出原子（PKA）向刃型位错（ED）碰撞级联与刃型位错的相互作用。研究发现，残余点缺陷的数量和分布与初始PKA与ED之间的距离有关。基于这一结果，我们全面总结了级联-位错相互作用的四种特征现象，包括少量相互作用、空位团簇的形成、点缺陷的汇效应以及子级联区域影响，这取决于峰值级联区域与位错线的重叠情况。然后提出了一个定性模型，以清楚地阐明这四种情况的潜在机制。考虑到位错是晶体固体微观结构的重要组成部分，我们的工作表明：晶体材料中预先存在的位错在辐照环境下可能会产生多种影响，在设计和改进抗辐射材料时应予以考虑。
