Decomposition of the γ phase in as-cast and quenched U-Zr alloys

Abstract

An investigation of the decomposition of the high temperature gamma phase in as-cast and quenched U-Zr alloys was conducted. Differential scanning calorimetry data clearly showed delta reversible arrow g transformations in alloys with <10 wt% Zr while XRD data did not contain any peaks which uniquely identify it&apos;s presence. Since delta phase forms via omega transformation, a comparison of the theoretical diffraction patterns for omega and delta revealed that the intensities of the peaks which uniquely identify the existence of delta when alpha-U is present, were either very weak, or were zero in omega, suggesting that the ambiguity can be explained if the phase present in these alloys is omega as opposed to delta. Our data are consistent with the presence of delta and omega in as-cast and quenched U-50Zr alloy, respectively, and (alpha+omega) in rest of the as-cast and quenched alloys. Based on the experimental data, the transformation sequence from gamma phase in U-Zr alloys is proposed.