LIBRARY OF CONGRESS WASHINGTON DC AEROSPACE TECHNOLOGY DIV
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The results of the effect of production conditions on the composition of UC are presented. The conditions studied included sintering and hot extrusion of UC powders and sintering of UC U alloys. An optimum regime for obtaining stoichiometric UC was established. Compacts of the initial mixture UO2 and carbon black, placed in beryllium oxide crucibles were sintered in a vacuum furnace with graphite heating elements. The UC briquets obtained were then ground into powder with particle sizes less than 10-15 microns. For hot extrusion of UC specimens, the graphite extrusion die was placed in a hermetically sealed metal vacuum chamber in which a pressure of about 10 mm Hg was maintained. The effect of extrusion pressure, temperature, and time on specimen density were studied. The porosity of hot-extruded specimens with length to diameter ratio equal to one was about 5. Compacts of UC powder and UC U mixtures with varying U content were placed in a graphite crucible and sintered in a vacuum furnace with graphite heating elements. After sintering for 2 hr at 2200 C, the porosity of UC was found to be 10. The introduction of metallic U sharply increased the density. With U content of 25 by volume and 2 hr sintering at 1700 C, it was possible to obtain a specimen with porosity of 5 or less.
- Ceramics, Refractories and Glass