Irradiation Effects in FeCrAl ODS Alloys

Results are presented for the FeCrAl ODS alloy containing nanoparticles with mean size of 21 nm. Structural analysis including HRTEM shows that the chemical composition of the Y2O3 oxide is modified with perovskite YAlO3 (YAP) and Y2Al5O12 garnet (YAG). Irradiation of these alloys was performed both with 400 keV Fe+ ions and a fluence Φ of 5x1016 cm-2 and a dual beam irradiation with 2.5 MeV Fe2+ (65 dpa) and 400 keV He+ (12 appm/dpa). He ions preferentially occupy the oxide-metal interfaces. He accumulation can occur around large nanoparticles but is not observed around small ones. In addition to structural changes, irradiation can also alter the mechanical properties such as hardness and indentation modulus. Nanoindentation experiments are suitable measurements to investigate these changes since the irradiation damage produced by the ion beam is in a thin surface layer. An increase in hardness with increasing radiation dose has been observed.