Interface roughening in irradiated oxide dispersion strengthened steels

Oxide Dispersion Strengthened steels are considered as promising candidates for nuclear applications as cladding tubes for GEN IV reactors. These materials are reinforced by a fine dispersion of nano-oxides whose semi-coherent flat interfaces constitute trapping sites for radiation-induced point defects. However, the sink strength of such interfaces may change under irradiation since the interfaces become damaged themselves. Therefore, the behavior of semi-coherent flat interfaces under irradiation is under concern. After ion irradiation up to 150 dPa at 500 °C, High Resolution Transmission Electron Microscopy images show that interfaces are no longer sharp but present an irregular mound morphology owing to the destabilization by the nuclear cascade collisions of incoming ions. Further, the kinetic roughening of the interfaces appears to increase with the irradiation dose. However, the low magnitude of the roughness suggests that the interfaces are remarkably stable under irradiation.