ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 22 June 2005
Page Count: 24

Plastic Deformation of Irradiated Zirconium Alloys: TEM Investigations and Micro-Mechanical Modeling

Onimus, F
Research Engineer, CEA/DEN, Service de Recherches Métallurgiques Appliquées, CEA-Saclay, Gif-sur-Yvette Cedex,

Béchade, J-L
Research Engineer, CEA/DEN, Service de Recherches Métallurgiques Appliquées, CEA-Saclay, Gif-sur-Yvette Cedex,

Prioul, C
Pr., Ecole Centrale Paris, Laboratoire de Mécanique des Sols, Structures et Matériaux, Châtenay-Malabry,

Pilvin, P
Pr., Université de Bretagne Sud-IUP Lorient, Laboratoire de Génie Mécanique et Matériaux, Lorient,

Monnet, I
Research Engineer, CEA/DEN, Service de Recherches Métallurgiques Appliquées, CEA-Saclay, Gif-sur-Yvette Cedex,

Doriot, S
Research Engineer, CEA/DEN, Service de Recherches Métallurgiques Appliquées, CEA-Saclay, Gif-sur-Yvette Cedex,

Verhaeghe, B
Research Engineer, CEA/DEN, Service d'Etude des Matériaux Irradiés, CEA-Saclay, Gif-sur-Yvette Cedex,

Gilbon, D
Research Engineer, CEA/DEN, Service d'Etude des Matériaux Irradiés, CEA-Saclay, Gif-sur-Yvette Cedex,

Robert, L
Research Engineers, Electricité de France, R&D Division, Materials and Mechanics of Components, Les Renardières, Moret sur Loing, Cedex,

Legras, L
Research Engineers, Electricité de France, R&D Division, Materials and Mechanics of Components, Les Renardières, Moret sur Loing, Cedex,

Mardon, J-P
Consulting Engineer, Framatome-ANP Nuclear Fuel, 10 Rue Juliette Récamier, Lyon Cedex 06,

(Received 15 March 2004; accepted 23 February 2005)

Abstract

TEM investigations have been performed on irradiated samples after deformation covering various testing conditions for different recrystallized Zr alloys. It is shown that for transverse tensile tests and internal pressure tests performed at 350°C, only basal channels are observed for strain levels up to uniform elongation, whereas only prismatic and pyramidal channels are observed for axial tensile test. Then, focusing on internal pressure testing, irradiation hardening and strain hardening behavior have been analyzed in detail and compared to TEM observations. It is proposed that dislocation channeling phenomenon leads to high strain incompatibility between channels and surrounding grains and therefore to high microscopic internal stresses. These high microscopic internal stresses are believed to induce strong kinematic hardening at the macroscopic scale, as suggested by the mechanical behavior analysis. Finally, a micro-mechanical model based on microscopic deformation mechanisms and using homogenization techniques is proposed, taking into account the observed channeling phenomenon.

Keywords:
dislocation channeling, irradiation, loop, internal stress, zirconium alloy

Paper ID: JAI12424
DOI: 10.1520/JAI12424
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