ABSTRACT
Uranium is the last element of the Periodic Table to exist in quantities greater than as transient decay. The main ores are the uranium dioxide, uraninite, of which pitchblende is a variant, and carnotite, which is a uranium vanadate produced hydrothermally in roll-front deposits. For non-nuclear applications, the metal is often alloyed with a low mass percentage of a range of these elements to improve its corrosion resistance. These include titanium, molybdenum, zirconium, niobium and chromium. The physical metallurgy of these alloy phases is very complex, as the processing often involves casting and quenching to retain homogeneity of alloy composition owing to the density difference between uranium and alloying components and the tendency to form intermetallic precipitates. The kinetics of uranium oxidation often follows a linear relation in water, steam or air. Considerable effort in the nuclear industry has characterized the structure of the phases of the uranium-water-oxygen system.
