Spark plasma sintering of silicon nitride/silicon carbide nanocomposites with reduced additive amounts

The spark plasma sintering technique was used to consolidate amorphous Si-C-N powder to obtain polycrystalline Si3N4/SiC ceramic composites. With decreasing additive content, the consolidation of the materials became increasingly dependent on solid-state sintering. The microstructure underwent a transition from a microcrystalline matrix with nanocrystalline second phase (micro-nano) to a nanocrystalline matrix with nanocrystalline second phase (nano-nano) when the yttria content was lowered to 3 wt.%.