A study on the mobility of 1/2 < 111 >(011)over-bar edge dislocation in low-carbon alpha-Fe and its interactions with damage cascade: On picosecond time scale using molecular dynamics simulations

SM Zamzamian and SAH Feghhi and M Samadfam, JOURNAL OF NUCLEAR MATERIALS, 527, UNSP 151806 (2019).

DOI: 10.1016/j.jnucmat.2019.151806

Molecular dynamics simulations were used to propose a closed-form expression for the mobility of the 1/2 < 111 >(011) over bar edge dislocation in low-carbon alpha-Fe (up to 0.1 at.% C) at temperatures of 300, 400 and 500 K and applied shear stresses of 10-100 MPa. Considering this parameter helps us to understand the effect of damage cascade on the dislocation mobility. The results confirmed that the point defect clusters at the thermal spike stage of the cascade (that they can be considered as an unstable precipitation-like phase), the distance of damage cascade relative to the center of the dislocation core and forming carbon-vacancy (C-V) complexes are some rather stronger obstacles for movement of the dislocation than isolated point defects. Then, the number of Frenkel pairs (either SIAs or vacancies) produced by different PKA energies in the case of with and without the presence of an immobile edge dislocation were also obtained and a mathematical expression was proposed. Surprisingly, we concluded that the presence of the dislocation considerably increases the number of point defects (on the picosecond time scale). (C) 2019 Elsevier B.V. All rights reserved.

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