DEFECT PRODUCTION AND ATOMIC MIXING BY DISPLACEMENT CASCADES IN NI3AL

Molecular dynamics simulations have been employed to investigate displ acement cascades in Ni3Al, with energy E-p in the range from 0.15 to 1 0 keV. The efficiency of production of Frenkel pairs declines with the increasing cascade energy in a fashion similar to that found recently for pure metals. The antisite defects are much more numerous than the Frenkel pairs, and their production efficiency increases with the inc reasing cascade energy. A new empirical relationship between the defec t number and damage energy is proposed, namely N-defect = AE(p)(m). A high proportion of the atomic mixing occurs in the ballistic phase and is larger for the Ni atoms, implying that the phenomenon is not purel y a liquid-like process.