Počet záznamů: 1  

A Numerical Analysis of Deformation Processes in Oxide Dispersion-Strengthened Materials – Influence of Dislocation-Particle Interactions

  1. 1. 0467048 - UFM-A 2018 RIV CH eng C - Konferenční příspěvek (zahraniční konf.)
    Záležák, Tomáš - Šiška, Filip - Stratil, Luděk - Luptáková, Natália - Šmíd, Miroslav - Bártková, Denisa - Svoboda, Jiří - Dlouhý, Antonín
    A Numerical Analysis of Deformation Processes in Oxide Dispersion-Strengthened Materials – Influence of Dislocation-Particle Interactions.
    Materials Structure & Micromechanics of Fracture VIII. Zürrich: Trans Tech Publications, 2017 - (Šandera, P.), s. 106-109. Solid State Phenomena, 258. ISBN 978-3-03835-626-4. ISSN 1662-9779.
    [MSMF8. International Conference on Materials Structure and Micromechanics of Fracture /8./. Brno (CZ), 27.06.2016-29.06.2016]
    Grant CEP: GA ČR(CZ) GA14-22834S; GA ČR GJ15-21292Y
    Institucionální podpora: RVO:68081723
    Klíčová slova: 3D discrete dislocation dynamics * metal matrix composites * precipitate hardening * high temperature creep
    Kód oboru RIV: JG - Hutnictví, kovové materiály
    Obor OECD: Materials engineering

    A recently developed 3D discrete dislocation dynamics (DDD) model is employed to study
    kinetics of dislocation ensembles subjected to high temperature creep in microstructures of metal
    matrix composites. We particularly focus on a migration of low angle tilt boundaries in a field of rigid
    impenetrable particles. This type of dislocation boundaries represents a typical microstructural feature
    mediating plastic deformation during the high temperature loadings.
    The article compares results of numerical studies that considered distinct dislocation-particle in-
    teractions in order to describe the response of dislocation structure to the applied stress. The results
    suggest that, regardless the details related to the dislocation-particle interactions, a critical applied
    stress always exists, below which the boundary migration process ceases [1, 2]. The existence of crit-
    ical threshold is confirmed by creep tests of ODS materials. This critical threshold, contrary to the
    classical Orowan stress, is proportional to the dislocation density. The displacements of individual
    dislocation segments on the micro-scale level reflect the changes in the dislocation-particle interac-
    tions quite sensitively. At the macro-scale level, the overall strain rate, which averages out velocities of
    all the individual dislocation segments, is also significantly influenced by the changes in dislocation-
    particle interaction.
    Trvalý link: http://hdl.handle.net/11104/0271178