Determination of the solidus temperatures of Zircaloy-4/oxygen alloys

Solidus temperatures have been measured for a series of Zircaloy-4/oxygen alloys, ranging from as-received (nominally O-free) Zircaloy to O-saturated Zircaloy. The data were obtained using a pyrometer-based differential thermal analysis technique. The results are in broad agreement with generally accepted values for the binary Zr-O system, except that there is a slight reduction in the solidus temperatures, caused by the presence of Sn, Fe and Cr in the pseudo-binary Zircaloy-O system. The solidus for O-saturated Zircaloy occurs at 2318 +/- 20 K, which is 145-185 K higher than the value assumed in many fuel-safety assessments. (C) 1999 Elsevier Science B.V. All rights reserved.