Displacement cascades in metals and ordered alloys. Molecular dynamics simulations

The aim of the present Molecular Dynamics (MD) simulations is a better understanding of the mechanisms associated with defect production and atomic mixing occurring in displacement cascades in irradiated metals and alloys. The cascades of energy up to 30 keV were investigated by parallel MD simulations in crystals with a reasonably large size of the simulation box, containing up to 2 millions of atoms. In order to separate the effect of the mass of atoms from the chemical effect on the defect production and the disordering in alloys, cascades were generated in Ni3Al and NiAl compounds where the Al atoms were artificially given the Ni mass. A series of artificial alloys FeAl, FeSb, FeAu, FeU were also investigated. Large interstitial clusters were found to be very mobile and a glide mechanism was pointed out. A sub-cascade formation mechanism was observed from cascades of energy equal to or higher than 5 keV and related to the quasi-channeling phenomenon.