Fundamental Materials Problems in Nuclear Reactors.

Mechanical Properties of Zircaloy-2 Neutron Irradiated to High Fluence

“…Dislocation channels had been observed in irradiated zirconium alloys in the 1960s-1980s [1][2][3][4][5], but understanding of the deformation channelling mechanism developed many years later [6][7][8][9][10][11][12][13]. Deformation of unirradiated zirconium alloys for low plastic strains was predominantly by prismatic slip of a-dislocations, because the critical resolved shear stress (CRSS) of the prismatic slip system was lower than that for the other slip systems [14].…”

“…Plastic deformation of neutron-irradiated zirconium alloys occurs in a highly inhomogeneous manner, forming bands or channels confined to localized regions [1][2][3][4][5][6][7][8][9][10][11][12][13]. This strain localization is produced by the annihilation of irradiation defects into channels that are dislocation free and can thus accommodate further deformation.…”

Development and Application of Materials Properties for Flaw Stability Analysis in Extreme Environment Service

“…Models for lattice strengthening, based on Orowon's theory for athermal bowing of dislocations around obstacles on a slip plane, were reviewed by Bement [13]. The expression for the athermal change in lattice strength is typically cited as the change in yield strength and is [12,13]:…”

“…The expression for the athermal change in lattice strength is typically cited as the change in yield strength and is [12,13]:…”

“…First, α should be considered a function of d. Second, the barrier hardening model applied in deriving α does not consider the strong temperature dependence of σ i [11,13]. If the non-irradiated change in lattice strengthening with test temperature has the same dependence as the irradiated change, then the change in yield strength would be temperature insensitive.…”