Collision cascade effects near an edge dislocation dipole in alpha-Fe: Induced dislocation mobility and enhanced defect clustering

JOURNAL OF NUCLEAR MATERIALS

卷:543

Article

Heredia-Avalos, S.¹  Denton, C. D.²  Moreno-Marin, J. C.¹  Martinez, E.³  Caturla, M. J.² 

[1] Univ Alacant, Dept Fis Engn Sistemes & Teor Senyal, Apartat 99, E-03690 Alacant, Spain

[2] Univ Alacant, Dept Fis Aplicada, Apartat 99, E-03690 Alacant, Spain

[3] Los Alamos Natl Lab, Theoret Div, T-1, Los Alamos, NM 87545 USA

关键词: Molecular dynamics;    Metals;    Dislocations;    Collision cascades;    Radiation damage;   

DOI  :  10.1016/j.jnucmat.2020.152459

来源: Elsevier

【 摘 要 】

Collision cascades near a 1/2 ( 111 ) {110} edge dipole in alpha-iron have been studied using molecular dynamics simulations for a recoil energy of 20 keV and two temperatures, 20 K and 300 K. These simulations show that the collision cascade induces the migration of the dislocations through glide along its slip plane. The motion of the dislocations starts at the peak of the collision cascade and expands a time scale much longer than the cascade duration, until restoring the equilibrium distance of the dipole, regardless of the damage produced by the cascade. At the initial stages, kinks are formed at the dislocation that enhance glide. When defects reach the dislocations, jogs are produced. We show that the initial dislocation motion is triggered by the shock wave of the collision cascade. The cascade morphology is also strongly influenced by the presence of the dislocations, having an elongated form at the peak of the displacement, which demonstrates the strong interaction of the dislocations with the cascade even at the early stages. Finally, we show that larger vacancy clusters are formed in the presence of dislocations compared to isolated cascades and that these clusters are larger for 300 K compared to 20 K. (C) 2020 Universidad de Alicante. Published by Elsevier B.V. All rights reserved.

【 授权许可】

Free