金属镍、铁和钨初级辐照损伤演化的分子动力学研究  

Molecular dynamics analysis of primary radiation damage evolution in nickel,iron,and tungsten

作　　者：应红[1,4] 温阿利 周岁茹 海雪 章文峰 任翠兰 施海宁[1,4] 黄鹤飞[2] YING Hong;WEN Ali;ZHOU Suiru;HAI Xue;ZHANG Wenfeng;REN Cuilan;SHI Haining;HUANG Hefei(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou 215004,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;National Engineering Research Center for Nuclear Power Plant Safety&Reliability,Suzhou 215004,China)

机构地区：[1]苏州热工研究院有限公司,苏州215004 [2]中国科学院上海应用物理研究所,上海201800 [3]西南石油大学新能源与材料学院,成都610500 [4]国家核电厂安全及可靠性工程技术研究中心,苏州215004

出　　处：《核技术》2023年第12期36-46,共11页Nuclear Techniques

基　　金：国家自然科学基金(No.52001322);上海市自然科学基金(No.23ZR1475700);四川省科技计划项目(No.2022YFSY0040)资助。

摘　　要：镍、铁和钨基合金常被用来作为反应堆的候选结构材料,在反应堆中面临中子辐照的严苛服役环境。本文采用分子动力学方法研究了金属镍、铁、钨三种金属材料的辐照级联过程,获得材料在不同温度(300~500 K)下、不同初级碰撞原子(Primary Knock-on Atom,PKA)能量(<20 keV)沿不同晶格方向(<135>、<122>和<100>)入射的辐照级联损伤过程。结果表明:金属镍和铁的稳态辐照缺陷数相当,当PKA能量较低(<5 keV)时,金属镍的稳态缺陷数比金属铁略少;而当PKA能量较高(>5 keV)时,金属镍的稳态缺陷数逐渐超过铁;在相同辐照条件下,金属钨的稳态辐照缺陷数最少,表现出更为良好的抗辐照性能。通过分析三种金属辐照级联过程中不同阶段的缺陷复合率及缺陷存活率,进一步理解其耐辐照损伤能力的差异。相关计算结果为理解不同金属的辐照性能提供数据支撑,作为金属初级辐照损伤数据集,为更大尺度的速率理论和团簇动力学等模拟材料辐照效应提供微观缺陷结构和参数。[Background]Nickel-,iron-and tungsten-based alloys are commonly used as structural materials of reactors.During their operational life,these alloys undergo intense neutron irradiation.[Purpose]This study aims to analyze the post-irradiation defect evolution and its mechanisms in these materials for comprehending the effects of irradiation on them.[Methods]The displacement cascades in nickel,iron,and tungsten were examined at various temperatures(300⁓500 K),primary knock-on atom(PKA)energies(<20 keV),and directions(<135>,<122>and<100>)by using molecular dynamics(MD)simulations.Firstly,the model was initially relaxed at each specified temperature under a canonical ensemble for 10 ps,applying periodic boundary conditions in every direction.Then,an atom was randomly chosen as a PKA and assigned kinetic energy to initiate the cascade collision simulation in the micro-canonical ensemble.Finally,the Open Visualization Tool package was employed for visualization and data analysis of the irradiation cascade processes.[Results]The simulation results reveal that nickel and iron exhibit similar steady-state defects.At lower PKA energies(<5 keV),nickel exhibits marginally fewer defects than iron.However,as the PKA energy surpasses 5 keV,the number of defects in nickel becomes slightly more than that in iron.Furthermore,under identical irradiation conditions,tungsten demonstrates superior radiation resistance,with fewer steady-state defects when compared with both nickel and iron.[Conclusions]The defect evolution during various cascade displacement phases in three metals and their defect recombination rates are crucial to understanding the disparities in radiation damage resilience.The derived results help to comprehend the radiation characteristics of these metals.Additionally,the primary radiation damage dataset compiled for these metals lays a foundation for further larger-scale simulations of their radiation attributes using rate theory or cluster dynamics methods.

关 键 词：镍 铁 钨 中子辐照 初级辐照损伤 分子动力学 

分 类 号：TL341[核科学技术—核技术及应用]