Investigation of some mechanical properties of Ti2O3-doped UO2 fuel pellets

In this study, ex-ADU (Ammonium diuranate) UO2 powders were doped with various amounts of Ti2O3 ranging from 600 ppm up to 3000 ppm. The doped UO2 powders were pressed to 50% theoretical density (TD) and sintered under 90% Ar + 10% H2 atmospheres at 1700 °C for 4 hours. Densities of the sintered samples were measured. The microstructure of the sintered pellets was investigated by optical microscopy and the average grain diameter was measured for each pellet by an image analysis system. The fracture toughness and hardness of the samples were also measured, revealing anisotropy in both properties.