Large scale molecular dynamics computer simulations were performed to study the role of the grain boundary during the cascade evolution in irradiated nanocrystalline Ni. At all primary knock-on atom energies in cascades near grain boundaries, the damage produced

after cooling down was vacancy dominated. Truncated stacking fault tetrahedra were easily formed at 10keV and higher primary knock-on atom energies. At the higher energies a complex partial dislocation network forms, consisting of truncated stacking fault tetrahedra. The grain boundary acted as an interstitial sink without undergoing major structural changes.

Stacking Fault Tetrahedra Formation in the Neighborhood of Grain Boundaries. M.Samaras, P.M.Derlet, H.Van Swygenhoven, M.Victoria: Nuclear Instruments and Methods in Physics Research B, 2003, 202, 51-5