Void growth and coalescence in triaxial stress fields in irradiated FCC single crystals

Chao Ling (1, 2) , Benoît Tanguy (2) , Jacques Besson (1) , Samuel Forest (1) , Félix Latourte (3)

1 CDM - Centre des Matériaux
2 LCMI - Laboratoire de Comportement Mécanique des Matériaux Irradiés
3 EDF - EDF

Void growth and coalescence, known as main mechanisms of ductile fracture, are investigated for irradiated FCC single crystals. Finite element simulations of voided unit cells are performed with a single crystal plasticity model accounting for strain hardening and softening associated with irradiation-induced defects. The simulations predict a rather brittle overall behavior for the voided irradiated single crystal at high stress triaxiality, with a large amount of local plastic deformation, which is consistent with experimental observations reported in the literature for stainless steels irradiated in fast reactors. Compared with unirradiated single crystals, irradiated crystals exhibit a higher void growth rate leading to an earlier void coalescence, which is caused by a stronger plastic slip localization in the region near the voids.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Chao Ling, Benoît Tanguy, Jacques Besson, Samuel Forest, Félix Latourte. Void growth and coalescence in triaxial stress fields in irradiated FCC single crystals. Journal of Nuclear Materials, 2017, 492, pp.157-170. ⟨10.1016/j.jnucmat.2017.04.013⟩. ⟨hal-01540836⟩