The atomic-scale modeling of dislocation-obstacle interactions in irradiated metals

Irradiation of metals with high-energy particles produces nano-scale defect clusters such as voids, dislocation loops, stacking-fault tetrahedra, and irradiation-induced precipitates. They are obstacles to dislocation glide and give rise to hardening and, in some conditions, deformation localization. Atomic-scale computer simulation has been developed to provide detailed information on how obstacle structure, stress, strain rate, and temperature influence these effects. Some recent results of modeling dislocations gliding under stress against obstacles in a variety of metals across a range of temperatures are considered. The effects observed include obstacle cutting, absorption, and drag. Although some processes can be represented within the continuum treatment of crystal defects, others cannot.