Multiscale observation of nano-oxide particles in oxide-dispersion-strengthened Cu alloys

Cu alloys with high durability and high thermal and electric conductivities are the key to achieving a more energetically efficient and eco-friendly future. Noble Zr-added oxide-dispersion-strengthened Cu alloys (ODS-Cu) with high strengths are promising materials for meeting all future service requirements. In this study, three-dimensional atom probe (3D-AP) and transmission electron microscopy (TEM) revealed that the majority of nano-oxide particles in the Zr-added ODS-Cu were novel yttria-stabilized zirconia (YSZ) particles with a diameter of less than 4 nm, which were completely different from Y2Zr2O7 and Y4Zr3O12 observed in other Zr-added ODS alloys. Multiscale observations including small-angle X-ray scattering (SAXS), 3D-AP, and TEM were performed to clarify the morphology of the oxide particles in the Zr-added ODS-Cu. Further strength enhancement through microstructural homogenization and specific incremental strength values were proposed. •Multiscale observation of oxide particles in Zr-added ODS-Cu was performed using small-angle X-ray scattering, 3D-AP and TEM.•Novel ultrafine YSZ nanoparticles with a diameter of less than 4 nm were confirmed to be mainly dispersed in the ODS-Cu.•Further strength enhancement and the specific incremental value of the ODS-Cu were predicted from the multiscale observation.