The effect of applied stress on -component dislocation loops in Zr-based alloys
Résumé
TMS 2015 Annual Meeting and ExhibitionMaterials and Fuels for the Current and Advanced Nuclear Reactors IVThe effect of applied stress on -component dislocation loops in Zr-based alloysN. Gharbi1 and R.M. Hengstler-Eger2, X. Feaugas3, D. Gilbon4, P.B. Hoffmann2, M.A. Kirk5, J.P. Mardon6, F. Onimus1 1CEA, DEN, Section for Applied Metallurgy Research, 91191 Gif-Sur-Yvette, Cedex, France2AREVA GmbH, Paul-Gossen-Str. 100, 91052 Erlangen, Germany3LaSIE, UMR CNRS 7356, Universite de La Rochelle, 17042 La Rochelle Cedex 01, France4CEA, DEN, Nuclear Materials Department, 91191 Gif-Sur-Yvette, Cedex, France5Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL60439, USA6AREVA NP, 10 rue Juliette Recamier, 69456 Lyon Cedex 06, FranceAbstractIrradiation-induced PWR fuel assembly deformation at high burn-ups is correlated with the appearance of specific irradiation defects -component dislocation loops. Industrial feedback suggests that a coupling between axial creep and stress-free growth could exist. Therefore, the effect of an external stress on -loop microstructure was studied through two complementary experiments on recrystallized Zircaloy-4 and M5 samples. Firstly, bending experiments were conducted under Zr irradiation beyond the c-loop incubation dose and thorough TEM analyses were performed after irradiation on many grains.Secondly, in-situ tensile tests were carried out under Kr irradiation to higher dose in a Transmission Electron Microscope allowing the observation of c-loop growth under stress in few grains. TEM observations showed that the applied stress has a minor effect on c-loop incubation dose. Moreover, their linear density decreases when a tensile stress is applied parallel to the c-axis. This effect was observed with different magnitudes, depending on experimental conditions.