Silicon Nitride–Silicon Carbide Nancocomposites Fabricated by Electric‐Field‐Assisted Sintering

Abstract

Starting with Si‐C‐N(‐O) amorphous powders, and using the electric field assisted sintering (EFAS) technique, silicon nitride/silicon carbide nanocomposites were fabricated with yttria as an additive. It was found that the material could be sintered in a relatively short time (10 min at 1600°C) to satisfactory densities (2.96–3.09 g/cm3) using 1–8 wt% yttria. With decreasing yttria content, the ratio of SiC to Si3N4 increased, whereas the grain size decreased from ∼150 nm to as small as 38 nm. This offers an attractive way to make nano‐nanocomposites of silicon nitride and silicon carbide.