Impact of ion and neutron irradiation on the corrosion of the 6061-T6 aluminium alloy

JOURNAL OF NUCLEAR MATERIALS

卷:553

Article

Quaireau, Sarah L'haridon¹  Colas, Kimberly¹  Kapusta, Benedicte¹  Verhaeghe, Benedicte¹  Loyer-Prost, Marie²  Gutierrez, Gaelle²  Gosset, Dominique³  Delpech, Sylvie⁴ 

[1] Univ Paris Saclay, DES Serv Etud Mat Irradies, CEA, F-91191 Gif Sur Yvette, France

[2] Univ Paris Saclay, DES Serv Rech Met Phys, CEA, F-91191 Gif Sur Yvette, France

[3] Univ Paris Saclay, DES Serv Rech Met Appl, CEA, F-91191 Gif Sur Yvette, France

[4] Paris Saclay Univ, IJCLab, Paris, France

关键词: Aluminium hydroxide;    Corrosion;    Microstructure;    Ion irradiation;    Neutron irradiation;   

DOI  :  10.1016/j.jnucmat.2021.153051

来源: Elsevier

【 摘 要 】

In nuclear research reactors, aluminium alloys are corroded and an aluminium hydroxide film covers their surface. Defects created by neutron irradiation can have a detrimental effect on this corrosion. In this study, two ion irradiations are performed on a 6061-T6 aluminium alloy. The first irradiation experiment aims at studying the effect of metal matrix irradiation on aluminium corrosion. The second irradiation experiment aims at studying the effect of hydroxide irradiation on aluminium corrosion. The displacement per atom is at most 2.5 dpa in the hydroxide film irradiated with Al ions of 1.2 and 5 MeV and at most 8 dpa in the aluminium matrix irradiated with Al ions of 1.8 MeV (calculated with SRIM). The effects of ion irradiation are investigated by TEM and SEM observations. The crystalline structure of aluminium hydroxide is studied by electron diffraction, mu-Raman and X-rays diffraction. In the aluminium hydroxide film (composed of a mix of bayerite, alpha-Al(OH)(3), and boehmite, gamma-AlOOH, before irradiation), ion irradiation causes formation of voids and dehydrates the aluminium hydroxide (nanocrystallites of -eta Al2O3 n are observed in the irradiated film). In the aluminium matrix, irradiation increases density of dislocations and amorphizes dispersoids. After ion irradiation, samples are corroded at 70 degrees C in 2.8L of demineralised water. The two irradiations increase aluminium corrosion. The second part of this study is about samples corroded in the Osiris nuclear research reactor, in water at 42 degrees C, with a pH of 6 and for 18 months. The aluminium hydroxide film observed on these samples has a layered microstructure composed of a compact inner layer, a thick intermediate layer and an outer layer of cuboid microcrystals. Silicon enrichment is observed in the inner layer. The effect of ion and neutron irradiation on aluminium corrosion is compared in this study and similarities are observed between ion and neutron irradiations. (C) 2021 Elsevier B.V. All rights reserved.

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