The sintering of uranium mononitride

Synthesis and Optimization of the Sintering Kinetics of Actinide Nitrides

“…McLaren et al [71] also showed that there is a slight relation between the compaction pressure and the final sintered density of the UN pellets in further studies. The final sintered density increased by approximately 2.5% as the compaction pressure increased from 275 MPa to 1100 MPa, However, pellets that were pressed at 1100 MPa exhibited de-laminations resulting in poor structural integrity of the sintered pellets.…”

“…As previously noted, the hydride prior to nitridation route was the primary source of UN synthesis throughout the 1960s but only a few authors report it [17,57,[60][61][62]71]. The reported documents tend to be brief and report very little on the the properties of UN and the effects of varying the temperature, time, or atmosphere on the kinetics and thermodynamics of the reaction.…”

“…Accordingly, this hydride-nitride method to the synthesis of UN and the previous ball-milling method both use pure uranium metal as the starting material. The work in this section is adapted from a limited number of available published works describing the synthesis of UN from pure uranium metal [17,57,[60][61][62]71]. …”

“…In 1965, McLaren et al [71] studied the effects of milling time, compaction pressure, sintering temperature, and sintering time on the final sintered density of UN. The powders were initially synthesized using a route that hydrided uranium metal prior to nitridation (similar to that presented Section 2.1.2 of this document).…”

“…50 gram batches of powder were milled in a high energy tungsten carbide vibratory mill. McLaren et al [71] reported particle sizes ranging from 0.01 to 3.0 μm and 0.01 to 0.5 μm after 8 and 128 hours of milling, respectively. However, the particle sizes were determined using optical techniques.…”