Irradiation studies on nano-scale single crystal copper by molecular dynamics simulation

Abstract

Abstract We report molecular dynamics (MD) simulation studies on the structure and tensile properties (temperature = 300 K and strain rate = 1010 s−1) of irradiated copper single crystals (101.8 Å× 50.54Å × 50.54Å) oriented along the [100] and [110] crystallographic orientations. Primary knock-on atom (PKA) method is used for radiation (0.5 keV to 5 keV). Structural studies indicate liquid like regions near the PKA region and are more in [110] orientation. The self-diffusivity (D) of copper in the PKA regions is found to increase from 4.05 × 10−5 m2/s at 1 keV irradiation energy to 27.36 × 10−5 at 5 keV irradiation energy in [110] orientation. However, no such relationship is observed in the [100] orientation. Vacancies, self-interstitials, and dislocations are more prominent in [100] orientation (dislocation density = 1 × 1016 m−2). Young’s modulus and yield strength decrease due to the formation of defects as anticipated.