Thermo-physical properties and microstructural characteristics of U-xZr (x = 40.5, 52 & 75 wt%) alloys

Abstract

Zr rich U-xZr (x = 40.5, 52 & 75 wt%) alloys were prepared by arc melting technique that improved the homogeneity and microstructural attributes of the alloys. The solidus-liquidus temperatures, phase transformation and crystallographic growth of these alloys were studied with spot technique, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and field emission scanning electron microscopic (FESEM) techniques. The solidus-liquidus temperatures were determined as 1895, 1948, 2015 K and 1951, 1996, 2046 K for 40.5, 52 and 75 wt% Zr alloys, respectively. In addition, the peritectoid transformation for 40.5 wt% Zr alloys was obtained at 868 K and the eutectoid transformation for 75 wt% Zr alloy was obtained at 864 K. Lattice parameters of the alloys were estimated through Reitveld refinement of the XRD patterns, and the variations of lattice parameters as a function of Zr content were compared with the existing literature data. It was observed that U-Zr alloys with 40.5 and 52 wt% Zr consisted of hexagonal δ-UZr2 phase only, however, alloy with 75 wt% Zr showed the presence of both δ-UZr2 and α-Zr phases. The compositional analysis by Davies and Gray method revealed that the maximum uncertainties in determining the composition for U and gravimetry for Zr were less than 0.5 wt% and 1 wt%, respectively.