Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing

Abstract

High entropy alloys (HEAs) are considered for applications in nuclear reactors due to their promising mechanical properties, corrosion and radiation resistance. In order to understand the irradiation effects in HEAs and to demonstrate their potential advantages over conventional austenitic stainless steels, we performed helium ion irradiation experiments with 20Cr-40Fe-20Ni-20Mn high-entropy alloy and 18Cr10NiTi steel under an identical condition. Both alloys have been irradiated to a dose of 4.8 displacement per atom (dpa) and a helium concentration of 11.7 at.% at room temperature. After subsequent annealing at 500 °C the microstructure evolution of irradiated materials was examined. The irradiation promotes the formation of a high density of bubbles in HEA and steel. Comparison of parameters of helium porosity in these materials has been done.