基于分子动力学模拟的锆辐照损伤及拉伸力学行为研究  

Study of irradiation damage and tensile mechanical behaviour of zirconium based on molecular dynamics simulation

作　　者：陈宏 王玉华[1] 李盈盈 Chen Hong;Wang Yuhua;Li Yingying(College of Science,Wuhan University of Science and Technology,Wuhan 430065,China;State Power Investment Corporation Central Research Institute,Beijing 102209,China)

机构地区：[1]武汉科技大学理学院,湖北武汉430065 [2]国家电投集团科学技术研究院有限公司,北京102209

出　　处：《武汉科技大学学报》2019年第4期265-271,共7页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金资助项目(11375136)

摘　　要：本文采用分子动力学方法模拟了不同初级离位原子(PKA)能量下单晶α锆的辐照损伤动态过程,以及辐照后的缺陷模型在沿[0001]单轴拉伸下的力学性能及微观结构演变。结果表明,随着PKA能量的增加,α锆晶体中辐照产生的Frenkel缺陷对数目稳步增加;单轴拉伸模拟结果显示,辐照产生的Frenkel缺陷对会显著降低单晶α锆的屈服强度,且随着PKA能量的增大,辐照材料的屈服强度呈缓慢逐渐下降的趋势;结合拉伸形变过程的微观结构演化可知,辐射产生的缺陷为位错环提供了成核位置,在较低的应变下即产生了大量位错,导致辐照后α锆的屈服强度大幅降低。In this paper,molecular dynamics simulations have been carried out to study the dynamic process of irradiation damage of single crystal α-Zr under different primary knock-on atom(PKA) energies,and the mechanical properties and microstructure evolution of the irradiated defect model under uniaxial stretching along [0001]direction. The results show that the number of Frenkel defect pairs in the irradiated α-Zr crystal increases steadily with the increase of PKA energy. Simulation results of uniaxial tensile tests show that the yield strength of single crystal α-Zr can be significantly reduced by Frenkel defect pairs generated by irradiation,and the yield strength of irradiated materials presents a slow and gradual decline trend with the increase of PKA energy. According to the microstructure evolution analysis of the tensile deformation process,it can be seen that radiation-induced defects provide nucleation sites for dislocation loop,and then a large number of dislocations are generated at a lower strain,resulting in a significant reduction in yield strength of irradiated α-Zr.

关 键 词：锆 辐照损伤 分子动力学模拟 级联碰撞 初级离位原子 FRENKEL缺陷 拉伸力学性能 

分 类 号：TG115.9[金属学及工艺—物理冶金]