Plastic Flow Localization in Irradiated Materials: A Multiscale Modelling Approach
When deformed after irradiation with energetic particles, metals exhibit increased yield stress and often undergo plastic flow localization and significant degradation of their mechanical properties. The effect limits the lifetime of the pressure vessel in most of the world's nuclear power plants, and threatens to severely limit the choice of materials for the development of fusion-based alternative energy sources. While these phenomena have been known for many years, an explanation of the underlying fundamental mechanisms and their relation to the irradiation field is lacking. Here, we use a multiscale simulation to show that the localization of plastic flow in defect-free channels results from combination of dislocation pinning by irradiation-induced defect clusters, unpinning by defect unfaulting and absorption, and cross slip of the dislocation the stress is increased. Double cross slip induces dipole formation and this limits the channel width. The ensuing plastic instability results in catastrophic mechanical failure.
Bibliographic Reference: Report: LRP 672/00 EN (2000) 14 pp.
Availability: Available from Centre de Recherches en Physique des Plasmas, Lausanne (CH)
Record Number: 200012775 / Last updated on: 2000-09-20
Original language: en
Available languages: en