S.M. Hafez Haghighat, R. Schäublin

Designing new materials is a challenging issue in the development of future fusion rectors. At present ferritic base steels are the main candidates for their structural components. However, radiation damage and large heat loads due to D-T fusion reaction degrade these materials. It is thus critical to have clear understanding of these effects. The complexity of these materials limits the identification of the microscopic phenomena underlying their mechanical properties and nowadays research recourses to simulations in a multiscale approach. Molecular dynamics simulation is commonly used to study the interaction of a dislocation with a defect under deformation of a nanometric sample of the basic phase of these materials, i.e. bcc-Fe. In this work we investigate the interaction of a dislocation with multiple defects at different distance relative to the dislocation line and relative to the dislocation glide plane. These results will be used to calibrate dislocation dynamics simulations that are used for mesoscale simulations. It appears that the stress field around defects disturbs the dislocation passage over or below it, although there is no direct interaction with the defect. The interaction of a dislocation with multiple defects on the glide plane with different distance relative to the dislocation line may soften or harden the interaction with one defect due to the attraction or repulsion of the bowed dislocation arms by another distant defect.

Molecular dynamics

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