AN EVALUATION OF THE PROPERTIES AND BEHAVIOR OF ZIRCONIUM-URANIUM ALLOYS

Data from a survey of the literature and other available information on zirconium--uranium alloys have been reviewed for the purpose of obtaining a coherent picture of current knowledge about the properties and behavior of zirconium--uranium alloys. The results of the survey were used to revise and extend the presentation of material gathered earlier in a similar study and reported in BMI1030 in August 1955. The constitution of zirconium-uranium alloys is discussed, and a constitutional diagram for the system is presented. The effects of oxygen and nitrogen, which are present in these alloys as contaminants, on alloy constitution ars shownin the form of ternary diagrams and in terms of their quantitative effects on the phases present. The transformation kinetics and the nature of the transformation of the high-temperature body- centered-cubic gamma phase to the phases stable at room temperature are described. Two regions are discussed: in the 20 to 70 wi. % uranium composition range, gamma, which is retained on quenching, transforms isothermally to the intermediate epsilon-phase structure by a diffusion-controlled nucleation-and- growth process; in alloys containing less than 20 wt.% uranium, gamma transforms martensitically to a strained alpha-zirconium structure on quenching, with the diffusion-controlled transformation of gamma to either epsilonmore » or alpha proceeding above the M/sub s/ temperature. Typical zirconium -- uranium alloy microstructures produced by working and by various heat treatments are shown, and a correlation of the structure with the manner in which it was produced and the resultant mechanical properties is attempted. Hardness, tensile, and creep data for zirconium--uranium alloys are tabulated and evaluated in terms of alloy constitution and transformation-kinetics behavior. Physical-property data for zirconium-uranium alloys are presented in tabular and graphical form. The best fabrication techniques for forging, hot and cold rolling, extruding, and swaging are detailed. The corrosion resistance of zirconium-uranium alloys in wafer at various temperatures and corrosion behavior as affected by alloy constitution are discussed. The effect of ternary additions on corrosion resistance is discussed, and pertinent data are tabulated. The influence of zircocium -uranium alloy constitution and properties on neutronirradiation behavior is discussed, and the general effects of irradiation upon these alloys are summarized. (auth)« less