You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.

    If you are an ASTM Compass Subscriber and this document is part of your subscription, you can access it for free at ASTM Compass

    Modeling the Interaction of Helium with Dislocations and Grain Boundaries in Alpha-Iron

    Published: 01 January 2008

      Format Pages Price  
    PDF (232K) 7 $25   ADD TO CART
    Complete Source PDF (11M) 240 $74   ADD TO CART

    Cite this document

    X Add email address send
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word


    Helium is a ubiquitous impurity in nuclear materials that can have significant deleterious effects on mechanical properties, including deformation and fracture. To determine ways to mitigate the effects of helium it is necessary to understand the behavior of helium with respect to its interaction with various microstructural features. Toward that end, we have employed molecular statics, molecular dynamics, and the dimer method of potential surface mapping to study the fate of helium in the vicinity of dislocations and grain boundaries in alpha-iron. Even at very low temperatures interstitial helium atoms can migrate to dislocations and grain boundaries, where they are strongly bound. The binding energies of helium to these microstructural features relative to the perfect crystal and the migration energies of helium diffusing within them have a strong correlation to the excess atomic volume that exists in these extended defects. Helium atom migration energies within the dislocations and grain boundaries studied are in the range of 0.4–0.5 eV. Helium “kick out” mechanisms have been identified within dislocations and grain boundaries by which interstitial helium atoms replace an Fe lattice atom, creating a stable He-vacancy complex that may be a nucleation site for an He bubble.


    iron, helium, molecular dynamics, dislocations, grain boundaries, computer simulation

    Author Information:

    Heinisch, H. L.
    Pacific Northwest National Laboratory, Richland, WA

    Gao, F.
    Pacific Northwest National Laboratory, Richland, WA

    Kurtz, R. J.
    Pacific Northwest National Laboratory, Richland, WA

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP46573S