摘要

The mechanical properties and fatigue crack propagation of irradiated Ni were investigated using molecular dynamic simulations. The irradiation specimens were obtained by cascade collision, and the primary knocked-on atom (PKA) energy was 10 keV. Tensile results showed that the irradiation led to the decrease in yield stress and yield strain, and also induced the variation of elastic modulus. Analysis of the microstructure in irradiated Ni showed that the irradiation defects inhibited the dislocation motion so that the extension of slip bands was limited, and caused the density of slip bands decreasing. Beside, the influence of irradiation defects on fatigue crack propagation was investigated. It was found that the irradiation defects could slow down the formation of blunting and slip bands and hindered effectively the fatigue crack propagation at 100 K. At 300 K, the crack attracted irradiation defects together, which accelerated the crack propagation with the formation of many slip bands.