The effect of dual Fe+/He+ ion beam irradiation on microstructural changes in FeCrAl ODS alloys

► High temperature annealing leads to phase transformation of oxide particles. ► Radiation induced hardening is stronger in heat treated HT-ODS materials. ► Hardness increase for simultaneous irradiation is larger than sequential irradiation. ► Helium filled cavities observed in a close surface area in irradiated samples.