| The investigation is aimed at a study of the relations between powder properties,
sintering treatments and the densification and microstructure development in urania
pellets. Urania powders for this study were prepared from ammonium diuranate by
decomposition and reduction at various temperatures, namely, 400°, 600°, 900°, 1200°
and 1500°C. Pellets prepared from these powders were sintered at temperatures in the
range of 1200° to 1700°C with different soaking periods.
The influence of (i) sintering temperatures, (ii) soaking periods at different temperatures,
(iii) intermediate soaks at varying time periods at various temperatures,
(iv) reheating of prepared sintered pellets and (v) rates of heating during sintering,
on the density and microstructure development of pellets was studied in this investigation.
The study revealed that urania pellets of specified density and grain development
can be prepared by first attempting to achieve densification and then continuing the
thermal treatments to attain the desired grain size and microstructure. |
