Mechanical behaviour near grain boundaries of He-implanted UO2 ceramic polycrystals

JOURNAL OF NUCLEAR MATERIALS

卷:483

Article

Ibrahim, M.^1,2  Castelier, E.¹  Palancher, H.¹  Bornert, M.²  Care, S.²  Micha, J. -S.³ 

[1] CEA, DEN, DEC, Ctr Cadarache, F-13108 St Paul Les Durance, France

[2] UPE, Ecole Ponts, IFSTTAR, CNRS,UMR 8205,Lab Navier, Champs Sur Marne, France

[3] CEA, INAC, F-38054 Grenoble 9, France

关键词: Mechanical analysis;    Polycrystal;    Stress singularity;    Light ion implantation;    X-ray micro-diffraction;    2D strain mapping;   

DOI  :  10.1016/j.jnucmat.2016.10.044

来源: Elsevier

【 摘 要 】

For studying the micromechanical behaviour of UO2 and characterising the intergranular interaction, polycrystals are implanted with helium ions, inducing strains in a thin surface layer. Laue X-ray micro diffraction is used to measure the strain field in this implanted layer with a spatial resolution of about 1 mu m. It allows a 2D mapping of the strain field in a dozen of grains. These measurements show that the induced strain depends mainly on the crystal orientation, and can be evaluated by a semi-analytical mechanical model. A mechanical interaction of the neighbouring grains has also been evidenced near the grain boundaries, which has been well reproduced by a finite element model. This interaction is shown to increase with the implantation energy (i.e. the implantation depth): it can be neglected at low implantation energy (60 keV), but not at higher energy (500 key). (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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