Evolution of the oxide-metal interface in the oxidation of Zr-2.5Nb tubes fabricated with different processes

Experimental Zr-2.5Nb tubes, manufactured with various fabrication routes, were oxidized in air, and oxide-metal interfaces were characterized using scanning electron microscopy. In the beginning of oxidation, the interface structure mimicked the substrate structure by forming oxide ridges on β-Zr phases. As the oxide grew, the interface structure evolved, developing a bumpy structure at tubes having higher oxidation rate or growing oxide granules at tubes having lower oxidation rate. (author)