Improvement of helium swelling resistance of nickel-based alloy via proper SiCNP dispersion

Abstract Ni-Mo-SiCNP alloy is a promising candidate as a structural material for building high-temperature molten salt reactors in the future. The irradiation damage resistance of this alloy is a key factor in determining its application prospects. In this study, Ni-Mo-SiCNP alloy samples containing different dispersion amounts (0.5, 1.5, and 2.5 wt.%) of SiCNP were irradiated with 1 MeV He+ ions at a dose of 3 × 1016 ion/cm2 at 750 °C. The evolution of helium bubbles was observed using transmission electron microscopy. The results show that with an increase in the dispersion amount of SiCNP, the number density of helium bubbles increases whereas the mean size decreases gradually. It is shown that a proper dispersion amount of SiCNP can effectively improve the helium swelling resistance of nickel-based alloys. Moreover, the related mechanism of the suppressed swelling was revealed.