Structure and mobility of the 1/2{112} edge dislocation in BCC iron studied by molecular dynamics

Ghiath Monnet, Dmitry Terentyev, Lorenzo Malerba

    Research outputpeer-review


    In this paper, we carried out atomistic calculations to investigate in detail the core structure and motion mechanism of the 1/2 <111 > {112} edge dislocation in a-iron. First, molecular statics simulations are used to characterise the dislocation-core structure in the framework of the Peierls–Nabarro model. It is shown that the accommodation of the distortion due to the insertion of the extra half-planes is not equivalent in the planes above and below the dislocation slip plane and that the relative atomic-displacement profile in the dislocation-core region is asymmetrical. Then, molecular dynamics simulations are used to study the mechanism of the dislocation motion at different temperatures. At low temperature, the dislocation is found to move by nucleation and propagation of kink-pairs along its line. Independently of temperature, when loading is performed in the twinning direction, the critical stress is found to be lower than the one corresponding to the antitwinning loading direction.
    Original languageEnglish
    Pages (from-to)1416-1426
    JournalActa Materialia
    Issue number5
    StatePublished - Mar 2009

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