Effects of Fe-Ions Irradiation on the Microstructure and Mechanical Properties of FeCrAl-1.5wt.% ZrC Alloys

Fe-13Cr-3.5Al-2.0Mo-1.5wt.% ZrC alloy was irradiated by 400 keV Fe+ at 400 degrees C at different doses ranging from 6.35 x 10(14) to 1.27 x 10(16) ions/cm(2) with a corresponding damage of 1.0-20.0 dpa, respectively, to investigate the effects of different radiation doses on the hardness and microstructure of the reinforced FeCrAl alloys in detail by nanoindentation, transmission electron microscopy (TEM), and atom probe tomography (APT). The results show that the hardness at 1.0 dpa increases from 5.68 to 6.81 GPa, which is 19.9% higher than a non-irradiated specimen. With an increase in dose from 1.0 to 20.0 dpa, the hardness increases from 6.81 to 8.01 GPa, which is an increase of only 17.6%, indicating that the hardness has reached saturation. TEM and APT results show that high-density nano-precipitates and low-density dislocation loops forme in the 1.0 dpa region, compared to the non-irradiated region. Compared with 1.0 dpa region, the density and size of nano-precipitates in the 20.0 dpa region have no significant change, while the density of dislocation loops increases. Irradiation results in a decrease of molybdenum and carbon in the strengthening precipitates (Zr, Mo) (C, N), and the proportionate decrease of molybdenum and carbon is more obvious with the increase in damage.

Automated summary

The irradiation of Fe-13Cr-3.5Al-2.0Mo-1.5wt.% ZrC alloy with Fe+ ions resulted in an increase in hardness, with saturation observed at higher doses. TEM and APT analysis showed the formation of high-density nano-precipitates and low-density dislocation loops at lower doses, while the density of nano-precipitates remained constant at higher doses. The decrease in molybdenum and carbon content in the strengthening precipitates with irradiation damage was also observed.