Intergranular film thickness of self-reinforced silicon carbide ceramics

The intergranular film of self-reinforced SiC ceramics prepared by hot pressing and further annealing with SiO2–Y2O3 and SiO2–Al2O3 as sintering additives was observed by high-resolution transmission electron microscopy. The film thickness of SiC ceramics with SiO2–Y2O3 was ∼1.2 nm whereas that of ceramics with SiO2–Al2O3 was ∼0.8 nm. Based on the refined continuum model, an explanation on the variation of thickness with sintering additives is given. It seems that the behavior of intergranular glassy film of SiC ceramics is akin to that of Si3N4 ceramics.