Molecular dynamics study of displacement cascades in Ni3Al I. General features and defect production efficiency

Abstract

Abstract The damage produced by displacement cascades in the L12 alloy Ni3Al at 100 K has been investigated by molecular dynamics using many-body interatomic potentials. 76 cascades ranging in energy from 0.15 to 5 keV have been simulated in order to study the effects of the energy and species of the primary recoil atom. Computer-generated colour plots have been used to visualize the nature and arrangement of the point defects produced in the cascade events. There is a change in cascade morphology at the end of the collisional phase for cascade energies in the range 1–2 keV, and separate subcascade regions can be seen in some cascades at 5 keV. Individual replacement sequences do not make a significant contribution to the final damage state. The efficiency of production of Frenkel pairs declines with increasing cascade energy in a similar fashion to that found recently for pure metals. Approximately 90% of the interstitials created in cascades are Ni-Ni dumbbell atoms, and the tendency of interstitials to...