MULTIPLE CASCADES REGIME IN FCC METALS - MOLECULAR-DYNAMICS SIMULATIONS AND CALCULATED HREM IMAGING

This study presents a simulation method which consists of three parts. The first one is classic molecular dynamics and is used to evaluate d isordered atomic configurations. The second one is an evaluation of th e electronic charge configuration of the type extended Debye-Hueckel. The third one calculates the HREM image of the lattice structure obtai ned from molecular dynamics. The simulation method is applied to colle ctive motions of PKAs displaced in a fee lattice with energies near th e displacement threshold. These conditions, which represent in a simpl ified manner e(-) irradiation, are aimed at investigating whether the defect growth kinetics shows ordering phenomena similar to the ones st udied in phase transition. Embryonic forms of ordered interstitial agg lomeration and unusual oscillatory behaviours of recrystallization are observed. The HREM calculations show that disorder is visible during its entire evolution.