Lawrence Berkeley National Laboratory

A series of in situ toughened, A1, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with A1 contents varying from 3 to 7 wt%. With increasing A1 additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline.