Atomic scale modelling of chromium diffusion and melting in α-iron and iron-chromium alloys using high-temperature molecular dynamics simulation

Dmitry Terentyev, Lorenzo Malerba, Pär Olsson, Marc Hou

    Research outputpeer-review

    Abstract

    An EAM interatomic potential to be used for radiation effect simulations in Fe-Cr systems has been recently proposed. In the present work, this potential is used to calculate, by means of classical molecular dynamics (MD), the diffusivity of solute Cr atoms in an Fe-12%Cr random alloy. Fe self-diffusivity is calculated as well, both in the alloy and in the pure metal, for comparison. In addition, the melting point for both the pure metal and the alloy, as predicted by the potential, has been determined and a comparison between the efficiency of vacancy and interstitial mechanisms for diffusion has been performed. This study allows the validity of the potential to be checked against experimental data outside its fitting range, while providing some insight into the description that this potential gives of irradiation effects. A correct prediction of the diffusivity of solute atoms at high temperature and the melting point are indeed an important pre-requisite for a correct prediction of ion mixing and point defect clustering within a displacement cascade during the thermal spike phase. The conclusion of the study is that the present potential is capable of reproducing with excellent accuracy both the diffusion coefficient and the melting point in Fe and in the Fe-Cr alloy. Atomic diffusion through interstitials is also seen to be a more efficient mechanism than through vacancies in the materials considered.
    Original languageEnglish
    Title of host publicationProceedings Volume 5400, Seventh International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering
    Place of PublicationBellingham, WA
    PublisherSPIE - The International Society for Optical Engineering
    Pages85-92
    Number of pages8
    Volume5400
    Edition2003
    ISBN (Print)9780819453235
    DOIs
    StatePublished - 5 Apr 2004
    Event2004 - Seventh International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering - Bellingham
    Duration: 5 Jun 20049 Jun 2005

    Conference

    Conference2004 - Seventh International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering
    Country/TerritoryUnited States
    CityBellingham
    Period2004-06-052005-06-09

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