Strain Localisation and Fracture of Nuclear Reactor Core Materials

The production of prismatic dislocation loops in nuclear reactor core materials results hardening because the impede motion. Yielding often occurs by a localised clearing through interactions with gliding dislocations called channeling. cleared channels represent softer material within which most subsequent deformation is localized. Channeling associated hypothetical pileup and intergranular cracking components although themselves do not amplify stress as one would expect from pileup. are similar appearance to twins leading possibility that sometimes mistakenly identified channels. Neither nor channels, bulk shears, produce same conditions on single plane. At high doses, when cavities produced (either He-stabilised bubbles at low temperatures or voids temperatures), there can be reduced ductility already an equivalent advanced stage microscopic necking. form preferentially grain boundaries precipitate incoherent twin/ε-martensite interfaces. higher planar density cavities, coupled incompatibility interface, preferential failure known He embrittlement. Strain localisation inter- intragranular dependent many factors ultimately microstructural nature. mechanisms described discussed relation materials.