Core/shell Structures Of Oxygen-rich Nanofeatures In Oxide-dispersion Strengthened Fe-cr Alloys

摘要

With the significant improvement in high temperature creep properties and resistance to radiation damage by addition of nanoscale oxide features, oxide-dispersion strengthened (ODS) ferritic/ martensitic alloys are potential candidates for structural applications in nuclear fusion reactors. The structure of the oxygen-rich nanofeatures was analyzed by atom-probe tomography in three ODS alloys: MA957, ODS Fe-12 wt % Cr, and ODS Eurofer-97. Although field evaporation and reconstruction of the precipitates suffer from artefacts, a core/shell structure is found even for very small precipitates. Precipitate cores are Y rich while shell regions are enriched in Ti, Cr, or V depending on alloy composition.