锆中层错金字塔与点缺陷的相互作用研究  

Study on the Interaction between Stacking Fault Pyramid and Point Defects in Zirconium

作　　者：谢荣轩 刘燕 许传龙 田晓宝 蒋文涛 王清远[1] 范海冬 Rongxuan Xie;Yan Liu;Chuanlong Xu;Xiaobao Tian;Wentao Jiang;Qingyuan Wang;Haidong Fan(Department of Mechanics,Sichuan University,Chengdu,610065)

机构地区：[1]四川大学力学系,成都610065

出　　处：《固体力学学报》2024年第3期289-301,共13页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金(12232008、12072211);重点实验室基金(2020JCJQLB05703)资助。

摘　　要：锆及其合金具有优异的力学性能和耐腐蚀性能、极小的热中子吸收截面,被用作核燃料包壳材料.在辐照环境中,锆合金内部产生大量的辐照缺陷,严重降低其力学性能和服役寿命.本文运用分子动力学方法研究了锆中层错金字塔与点缺陷(间隙原子、空位)的相互作用,发现当温度为0K和300K时层错金字塔只能吸收间隙原子;当温度为600 K时层错金字塔可以同时吸收间隙原子和空位.为了解释此现象,本文计算了间隙原子/空位与层错金字塔的结合能,结果表明结合能与点缺陷的类型/位置有关:间隙原子的结合能远大于空位结合能,故间隙原子更易于被吸收;同时距离层错金字塔越近,结合能越大,两种点缺陷也更易于被吸收.本文的模拟成果有助于学界认识锆中辐照缺陷的长大机制,为锆合金的抗辐照设计提供理论指导.Zirconium and its alloys are widely used as fuel cladding in nuclear reactors because they have good mechanical properties,good corrosion resistance,and small thermal neutron absorption cross-section.Under irradiation,a large number of irradiation-induced defects are generated,which greatly reduce the mechanical properties and service life of zirconium alloys.In this work,molecular dynamics method is used to study the interaction between stacking fault pyramid(SFP)and point defects(self-interstitial atoms(SIAs),vacancies).At 0 K and 300 K,the SFP absorbs SIAs only;At 600 K,the SFP absorbs both SIAs and vacancies.In addition,the size of SFP has a negligible effect on the interaction mechanism.The binding energy between SIAs/vacancies and SFP is calculated.The binding energy of SIAs is much higher than that of vacancies,and SIAs are absorbed easily.Current work provides new insight into understanding the growth mechanism of irradiation-induced defects in zirconium.

关 键 词：锆 分子动力学 辐照点缺陷 层错金字塔 

分 类 号：TL34[核科学技术—核技术及应用]