In situ Transmission Electron Microscopy He+ implantation and thermal aging of nanocrystalline iron

JOURNAL OF NUCLEAR MATERIALS

卷:482

Article

Muntifering, Brittany^1,2  Fang, Youwu²  Leff, Asher C.³  Dunn, Aaron^1,4  Qu, Jianmin^2,5  Taheri, Mitra L.³  Dingreville, Remi¹  Hattar, Khalid¹ 

[1] Sandia Natl Labs, Albuquerque, NM 87185 USA

[2] Northwestern Univ, Dept Civil & Environm Engn, Evanston, IL 60208 USA

[3] Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA

[4] Georgia Tech CNRS, Georgia Inst Technol, George W Woodruff Sch Mech Engn, UMI 2958, F-57070 Metz, France

[5] Tufts Univ, Sch Engn, Medford, MA 02155 USA

关键词: Nanocrystalline iron;    In situ TEM;    Helium implantation;    Annealing;   

DOI  :  10.1016/j.jnucmat.2016.10.001

来源: Elsevier

【 摘 要 】

The high density of interfaces in nanostructured materials are hypothesized to improve radiation tolerance compared to coarse-grained materials. In order to investigate the roles of vacancies, selfinterstitials, and helium, both room temperature in situ TEM He+ implantation and annealing, as well as high temperature He+ implantation was performed on nanocrystalline iron. Dislocation loops are formed by the accumulation of mobile point defects rather than by displacement cascades at intermediate temperatures. Around 600 degrees C, loops disappeared through gradual shrinking, which is hypothesized to correspond to the annihilation of self-interstitial atoms by mobile vacancies that also resulted in cavity formation. The room temperature implantation resulted in cavities evenly distributed throughout the grain after annealing, whereas cavities were predominately observed at grain boundaries for the elevated temperature implantation. This difference is associated with the formation of stable helium-vacancy complexes in the grains during room temperature implantation, which is not present during high temperature implantation. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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