物理学报2023，Vol.72Issue(24)：121-128,8.DOI:10.7498/aps.72.20230651
<100>间隙型位错环在纯钨及含氦杂质钨(010)表面下运动行为的分子动力学模拟
Molecular dynamics simulation of dynamic migration of <100> interstitial dislocation loops under (010) surfaces of pure W and W containing helium impurity
摘要
Abstract
In the fusion irradiation environment,dislocation loop defects occurring under plasma-facing tungsten surface affect its mechanical properties and hydrogen/helium retention.This paper studies the dynamic behaviors of a<100>loop with a radius of 1 nm under the W(010)surface by using molecular dynamics simulation at the atomic level.It is found that the dislocation loop direction,bulk temperature,depth,and helium atoms can greatly affect the motion of dislocation loops,showing that the b//n dislocation loop,where b is the Burgers vector and n denotes the surface normal direction,tends to move towards the surface and the b⊥n dislocation loop tends to stay in the material.In the course of its migration,the habit plane of dislocation loop may change and the internal stress decreases gradually.The probability of a b//n dislocation loops escaping from the surface is over 90％when the temperature is higher than 800 K and their initial depth is less than 5 nm.The b⊥n dislocation loop can escape from the surface when the temperature is 800 K and the initial depth is less than 2 nm.It is found that<100>dislocation loops decompose into 1/2<111>dislocations at elevated temperatures.Helium atoms impede the migration of dislocation loops and increase their retention time.The existence of dislocation loops results in the uneven distribution of helium atoms under the W surface,and will potentially affect the surface morphology of tungsten.关键词
分子动力学模拟/位错环/映像力/氦Key words
molecular dynamics simulation/dislocation loop/image force/helium引用本文复制引用
秦梦飞,王英敏,张红玉,孙继忠..<100>间隙型位错环在纯钨及含氦杂质钨(010)表面下运动行为的分子动力学模拟[J].物理学报,2023,72(24):121-128,8.基金项目
国家磁约束核聚变能发展研究专项(批准号:2019YFE03030004)和国家自然科学基金(批准号:12275040)资助的课题.Project supported by the National MCF Energy R&D Program of China(Grant No.2019YFE03030004)and the National Natural Science Foundation of China(Grant No.12275040). （批准号:2019YFE03030004）
