Study on the Thermal Shock Resistance of Si3N4/TiC Nanocomposite Ceramic Tool Materials

By adding nano Si3N4 and nano TiC particles into the micro Si3N4 matrix, the Si3N4/TiC nanocomposite ceramics were fabricated via hot pressing technique with Al2O3 and Y2O3 as sintering additives. The thermal shock resistance of Si3N4/TiC nanocomposites were investigated by means of indentation-quenching and quenching-retained strength testing methods. The results revealed that the composite containing 10 wt.% nano Si3N4 particles and 15 wt.% nano TiC nano particles was possessed of the highest thermal shock resistance, with its critical temperature difference being 700~750. The toughening and strengthening mechanisms by the nano particles addition are deem to be the essential course for the improved thermal shock resistance.