Observation of deep dislocation structures and “long-range effect” in ion-implanted α-Fe

The results of experimental investigations of “long-range effect” by ion implantation into α-Fe are presented. C, Fe, W, Hf and Ar ions were implanted into α-Fe in continuous and pulse-periodic regimes. The ion energy varied in the range 40–150 keV and the irradiation dose varied in the range 1 × 10 15-1 × 10 18 ions cm -2. It has been established that dislocation structures are formed in the near-surface layer of pure metals by ion implantation. The thickness of the near-surface layers with the dislocation structure induced by ion implantation is in the range 20–100 μm. Stress measurements and calculations in the near-surface layers by ion implantation show that the stresses are considerably greater than the yield strength. The stresses result in the plastic deformation of the near-surface layers of the irradiated materials. The plastic deformation is the main reason for the dislocation structure development.