Twinning and recrystallisation as crack tip deformation mechanisms during fracture

Abstract We report atomistic studies of the deformation mechanisms in the crack tip region during low temperature fracture of bcc Fe single crystals. The large-scale simulations use empirical potentials to study the crack tip response. The twins are formed by the emission of partial dislocations in adjacent slip planes of the {112} type. In addition to twinning, the results show the nucleation of new grains in the crack tip region. The twinning and stress-induced recrystallisation phenomena are also observed in fully three-dimensional digital samples of nanocrystalline Fe. Acknowledgements This work was supported by the Office of Naval Research, Division of Materials Science.