Microstructure and Deformability of Cast Zr-Nb-Fe-O Alloy with High Iron and Oxygen Content

Abstract

In order to investigate the possible effect of the scrap inclusions in recycling, microstructure and deformability of Zr-Nb based alloys cast with the addition of iron and iron oxide were studied. No visible iron oxide inclusions were observed in the arc-melted cake, suggesting that Zr and Fe2O3 reacted completely to dissociate Fe2O3 into Fe and O in the Zr. No oxide peaks were observed by XRD analyses. In Zr-Nb alloy melted with iron oxide, the oxygen content reached up to 3150 ppm. Zr-1.2 Nb alloys with high oxygen contents exhibited needle-shaped α phase. and the the thickness of needles decreased. In Zr-1.2Nb alloys with over 2000 ppm they are brittle and cracked during rolling process. In some region of the fracture surface brittle fracture feature such as vein-like pattern was observed. In the fractograph, no brittle second phase particles were observed. EDS spectra. It is apparent that Zr-Nb alloys with the addition of iron oxide during the handling of scrap materials exhibit the extremely brittle behavior.