Roles of Intergranular Delta-Hydrides in the Failure of Hydrided Zr Alloys

Abstract

Roles of intergranular delta-hydrides in the failure of hydrided Zr alloys are studied based on the analysis of the link-up of microcracks produced due to the hydride rupture and the thermodynamic modelling of the stress-induced formation of inter- and intra-granular hydrides. Our results show that the intergranular hydrides may be more deleterious to the ductility than the intragranular ones and the fracture mechanism of the hydrided Zr alloys is related to the grain-boundary structure, the orientation of the Zr grains along the grain boundaries and the applied stress.