Solute segregation and interface stability in ODS ferritic alloys: A first-principles study with experimental validation

We investigate solute segregation and interface stability in oxide dispersion-strengthened (ODS) ferritic alloys by integrating density-functional-theory (DFT) calculations with correlative experimental validation. DFT predicts the Fe/Y 2 Zr 2 O 7 interface to be top-coordinated and oxygen-rich, exhibiting a low formation energy of 0.20-0.37 J/m 2 . Strong segregation of Ni and Al to interfacial Fe sites is also predicted, enabling the formation of a nanoscale interfacial shell around Y 2 Zr 2 O 7 nanoparticles. This atomic-scale architecture is directly confirmed via high-resolution transmission electron microscopy and 3D atom probe tomography. Segregation-enhanced interfacial bonding concurrently elevates strength and ductility, demonstrating that strategic micro-alloying can engineer interface properties for enhanced mechanical performance. These findings establish critical design principles for multi-element micro-alloyed ODS ferritic alloys in advanced nuclear applications.