Dose dependence of irradiation hardening of binary ferritic alloys irradiated with Fe3+ ions

The effects of alloying elements on irradiation hardening behavior of various Fe-based binary alloys irradiated with Fe3+ ions were investigated by using the nano-indentation technique. Ion-irradiations with 6.4 MeV Fe3+ were performed on Pure-Fe, Fe–1Cr, Fe–1Mn, Fe–1.5Mn, Fe–1Ni, Fe–1Cu, and Fe–1Mo to nominal displacement damage levels of 0.1, 0.3 and 1 dpa, at a damage rate of 1 × 10−4 dpa/s at 290 °C. Significant irradiation hardening was observed in the Fe–1Mn, Fe–1.5Mn and Fe–1Ni as well as in the Fe–1Cu, but not in the Pure-Fe, Fe–1Cr and Fe–1Mo, after irradiation to 1 dpa at 290 °C. The dose dependence of the irradiation hardening was well explained for all the alloys by the saturation fitting model. Microstructural observation suggested that irradiation induced matrix defects in Fe–Mn binary alloy promoted the irradiation hardening.