Ion Irradiation Defects and Hardening in FeCrAl Alloy

Abstract

The self-ion irradiation experiments of FeCrAl and Y−FeCrAl alloys are carried out at 330 °C to 1–10 displacements per atom (dpa). The formation of dislocation loops in these alloys is investigated by transmission electron microscopy (TEM) and nano-indentation tests are used to assess the irradiation hardening. A large number of dislocation loops are formed after irradiation, and dislocation network gradually develops above 2.5 dpa. The average size of dislocation loops increases while the number density decreases when the dose was increased. In comparison to a/2<111> dislocation loops, a<100> dislocation loops have a larger average size and higher proportion. Higher temperatures and dose rate can increase the proportion of a<100> dislocation loops. As the dose is increasing, irradiation hardening increases. The addition of yttrium increases the proportion of a<100> dislocation loops and reduces the irradiation hardening due to the high binding energy between yttrium atom and vacancy.