聚变材料钨辐照后退火形成的位错环特性及inside-outside衬度分析  

Analysis of dislocation characteristics and inside-outside contrasts in irradiated and annealed tungsten as a fusion reactor material

作　　者：徐驰 万发荣[3] Xu Chi;Wan Fa-Rong(Key Laboratory of Beam Technology of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China;Institute of Radiation Technology,Beijing Academy of Science and Technology,Beijing 100875,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100086,China;Innovation Center of Nuclear Materials for National Defense Industry,Beijing 102413,China)

机构地区：[1]北京师范大学核科学与技术学院,射线束技术教育部重点实验室,北京100875 [2]北京市科学技术研究院,辐射技术研究所,北京100875 [3]北京科技大学材料科学与工程学院,北京100086 [4]国防科技工业核材料技术创新中心,北京102413

出　　处：《物理学报》2023年第5期278-288,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:1210050304);国防科技工业核材料技术创新中心(批准号:ICNM-2022-YZ-02)资助的课题。

摘　　要：对纯钨透射电镜薄膜样品在400℃进行了58 keV、1×10^(17)cm^(-2)(约0.1 dpa)的氘离子辐照,辐照后进行了900℃/1 h的退火处理.离子辐照产生了平均尺寸为(11.10±5.41)nm,体密度约为2.40×10^(22)m^(-3)的细小位错环组织,未观察到明显的空洞组织.辐照后退火造成了位错环尺寸的长大和体密度的下降,分别为(18.25±16.92)nm和1.19×10^(22)m^(-3).通过透射电镜的衍射衬度分析,判断辐照后退火样品中的位错环主要为a/2<111>类型位错环.通过“一步法”inside-outside衬度分析判断位错环为间隙型位错环.辐照后退火还造成了较大位错环之间接触融合,形成不规则形状的大型位错环.此外,退火后样品中还观察到了尺寸为1—2 nm的细小空洞组织.Tungsten is an important candidate of plasma-facing material for fusion reactors.Its irradiation response,especially the post-irradiation annealing(PIA)behavior needs further investigating.In addition,the practice of the"inside-outside"contrast method of determining the characteristics of irradiation induced dislocation loops has not been utilized frequently,and the present research serves as an example to present some practical considerations.In the present work,a tungsten thin-foil specimen is irradiated at 400℃with 58 keV D+to a final fluence of 1×10^(17)cm^(-2),corresponding to a dose of about 0.1 dpa.The specimen is prepared through the electro-polishing method by using a NaOH based electrolyte.The ion irradiation is carried out directly on the electro-polished specimen.The irradiated specimen is followed by isothermal annealing at 900℃for 1 h.The as-irradiated and post-irradiation annealing modified defects are investigated with a transmission electron microscope(TEM)operated at 200 kV.The irradiation defects are characterized by using TEM bright-field imaging for the same imaging field with different g vectors around the three major zone axes:the[001],[111],and[Oil]zone axis of the body-center cubic lattice of W.For each g vector,the±g are characterized,and the corresponding contrast-extinctions and"inside-outside"contrasts of selected dislocation loops are identified.The indices of the g vectors around different zone axes are assigned consistently with the Kikuchi map.As a result,the D+irradiation increases a fine distribution of dislocation loops with an average size of(11.10±5.41)nm and a bulk density of 2.40×10^(22)/m^(3).Voids are not observed obviously.The post-irradiation annealing causes the loop size to increase and the loop density to decrease,with numbers of(18.25±16.92)nm and 1.19×10^(22)/m^(3),respectively.Through the contrast-extinction analysis,the dislocation loops in the irradiated and annealed specimen are identified to be a/2<111>-type dislocation loops.The post-irradiation ann

关 键 词：钨 离子辐照 位错环 inside-outside衬度 

分 类 号：TL627[核科学技术—核技术及应用]