Effect of large seeds addition on microstructural development of SiC sintered with oxynitride glass

The introduction of large alpha -SiC seeds into fine beta -SiC with Y-Mg-Si-Al-O-N glass accelerated the growth of plate-shaped SiC grains during annealing while the addition of large beta -SiC seeds into fine beta -SiC led to the equiaxed grains. The given results show that in situ-toughened microstructure can be obtained in beta -SiC with oxynitride glass, which has benefits in reducing the weight loss during sintering and annealing, compared with the conventional oxide additives such as Al sub(2)O sub(3) and Y sub(2)O sub(3).