Preparation of UN, α/β‐U 2 N 3, and Their Converted UN Pellets

Key Points

• This work aims to synthesize high-density UN pellets using a carbothermic reduction and nitridization method.
• Synthesized low carbon α-U2N3 and β-U2N3 powders from U3O8 by CTR-N.
• Added α-U2N3 or β-U2N3 to UN powder for spark plasma sintering (SPS).
• Conducted SPS at temperatures above 1650°C and pressure of 55 MPa in vacuum.
• UN pellets achieved above 95% theoretical density with optimal U2N3/UN ratio of 0.1.
• Higher U2N3/UN ratios (>0.5) resulted in decreased pellet density.
• Improved pellet density compared to using UN powder alone.