MD simulations of collision cascades in the vicinity of a screw dislocation in aluminium
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Date
2015-05-15
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Elsevier
Abstract
Molecular dynamics has been applied to study the interaction of collision cascades with 1=2h110i screw dislocations in aluminium. Primary knock-on atoms (PKA) with energy EPKA ¼ 5 keV were initiated in Al crystals at temperatures ranging from 100 K to 600 K at different distances from the dislocation line. Capture of the displaced atoms from the collision cascade region by the dislocation core has been observed at all simulation temperatures and led to the formation of a helical dislocation segment. Apart from that, in the material subjected to external loading a displacement cascade in the vicinity of a screw dislocation can trigger dislocation cross-slip. Under applied stress the dislocation unpins from the helical segment with the formation of a mobile dislocation loop with 1=2h110i Burgers vector. The number of residual vacancies and self-interstitial atoms produced in collision cascades near 1=2h110i screw dislocations is evaluated and compared with the number of Frenkel pairs formed in collision cascades in the pristine material under the same irradiation conditions. © 2013 Elsevier B.V.
Description
Proceedings of the 11th Computer Simulation of Radiation Effects in Solids (COSIRES) Conference Santa Fe, 24-29 July 2012, New Mexico, USA.
Keywords
Molecular dynamics method, Aluminium, Damage, Irradiation, Screw dislocations, Velocity
Citation
Voskoboinikov, R. E. (2013). MD simulations of collision cascades in the vicinity of a screw dislocation in aluminium. Paper presented at the 11th Computer Simulation of Radiation Effects in Solids (COSIRES) Conference Santa Fe, New Mexico, USA, 24-29 July 2012. In In Uberuaga, B. P., Caro, A., & Smith, R. (Eds), Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 303, 104-107. doi:10.1016/j.nimb.2013.01.021