Strain-induced dissolution of Y-Ti-O nano-oxides in a consolidated ferritic oxide dispersion strengthened (ODS) steel

The present study shows the influence of severe plastic deformation on highly stable Y-Ti-O nano-oxides present in ferritic ODS alloys used for nuclear applications. An innovative strain path implying alternated compressions was used to deform the material to an equivalent plastic strain of 13. Energy Filtered Transmission Electron Microscopy and Small Angle Neutron Scattering revealed the strain-induced dissolution of the Y-Ti-O nano-oxides. It appears to be the first time that dissolution of such particles is clearly observed after deformation. Annealing the material enables to re-precipitate the nano-oxides. These results show a strong analogy with the mechanical alloying of ODS powder.