Thermophysical properties of several nitrides prepared by spark plasma sintering

Relatively high-density nitride pellets of TiN, ZrN, DyN, UN and their composites have been prepared by spark plasma sintering (SPS) technique without any milling process and sintering additive. The sintering process finished within 30 min for all the samples. The short sintering time and moderate sintering temperature strongly prohibited the grain growth in the sintering process. The SPS-prepared sample showed high Vickers hardness due to the small grain size. Despite of the grain size, the thermal conductivity remains the high value. The result indicates that the impurity layer on particle surface was removed in SPS process. The SPS pelletizing permits easy densification of nitrides without any deterioration of thermal properties, considered to be suitable as a preparation method of nitride fuels.