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| 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 |
| 投稿时间：2019-03-08 |
| DOI： |
| 中文关键词: 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 |
| 英文关键词: Zr irradiation damage molecular dynamics simulation displacement cascade primary knock-on atom(PKA) Frenkel defect tensile mechanical property |
| 基金项目:国家自然科学基金资助项目(11375136). |
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| 中文摘要: |
| 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。 |
| 英文摘要: |
| 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. |
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