Helium ion irradiation induced swelling and hardening in commercial and experimental ODS steels

Low swelling is found in both alloys, although the PM2000 shows a lower resistance, with an increased swelling of ∼0.8% dpa−1 at 600 °C, while the 15CRA-3 presents an almost constant swelling of around 0.4% dpa−1 throughout the complete temperature range. Radiation hardening follows a similar trend, whereby hinting towards an annealing mechanism taking place at the interfaces between the very fine distribution of Y2O3 nanoparticles and the matrix, interfaces which act as sites of enhanced point defect recombination as well as traps for the implanted helium.