Effect of dispersed particles on generation of defect-free channels and stability of deformation of neutron irradiated metals

Dislocation-kinetics equations are used to consider the effect of precipitates and disperse particles on the conditions of formation of defect-free channels and the appearance of a yield drop and a yield plateau in the stress-strain curves of neutron-irradiated metals and alloys. It is found that, at a volume particle concentration higher than a certain critical value depending on the radiation dose, no channels form, while the yield drop and yield plateau in the stress-strain curves disappear. A high concentration of disperse particles in a metal strongly decreases the uniform strain above which plastic instability in the form of a neck appears in a tensile specimen. The theoretical results are illustrated by available experimental data for copper and copper alloys