Thermal shock resistance of Si3N4/SiC nanocomposites fabricated from amorphous Si-C-N precursor powders

The thermal shock resistance of Si3N4/SiC nanocomposites fabricated from the amorphous Si-C-N precursor powder was investigated by a water-quenching method. The SiC dispersion decreased the critical temperature difference (Delta T-c) of Si3N4, although it improved significantly the fracture strength. This decrease in Delta T-c was discussed associated with the variations in mechanical and thermal properties by the nano-sized SiC dispersions as well as temperature difference dependence of the surface heat transfer coefficient at the water-ceramic interface.