Microstructural Characteristics of DU-xMo Alloys with x = 7-12wt%

Microstructural, phase, and impurity analyses of six depleted uranium-molybdenum alloys were obtained using optical metallography, x-ray diffraction, and carbon/nitrogen/oxygen determination. Uranium-molybdenum alloy foils are currently under investigation for the possible conversion of high-power research reactors to accommodate the use of low-enriched uranium fuel. Understanding basic microstructural behavior of these foils is an important consideration in determining the impact of fabrication processes and in anticipating performance of the foils in a reactor. Average grain diameter decreased with increasing molybdenum content, while the degree of mechanical deformation banding increased with increasing molybdenum content. A lattice parameter, which provided information on stress-corrosion cracking behavior, decreased with increasing molybdenum content, and no significant degree of crystallographic ordering was caused by processing and post-processing conditions employed in this study. Impurity concentration, specifically carbon when it is in solution with the host matrix, inhibited the degree of microstructural recrystallization but did not appear to impact other microstructural traits, such as ?-phase retention or lattice parameter.