Reactive hot pressing of nonstoichiometric uranium dioxide

摘要: High density UO2+x pellets have been produced by reactive hot pressing uranyl oxalate at temperatures up to 700°C. Rapid densification occurred during the decomposition reactions resulting in densities range 90 92 pct of theoretical. A 98 theoretical value was achieved further hot-pressing 650° 700°C for 30 min. This behavior can be related nonstoichiometry and submicron sized particles reactions. The kinetics powder compacts this were studied temperature 500° results analyzed utilizing models proposed Fryer. activation energy 53 kcal per mole, obtained from analysis is same as that creep nonstoichiometric urania 975° 1400°C, suggesting mechanism controlling rate final stage may a process.