Effect of grain size on thermal shock resistance of Al2O3-TiC ceramics

The thermal shock resistance of pure hot-pressed alumina and Al2O3-TiC composites was studied in order to assess the influence of Al2O3 and TiC starting powder size. Al, and Al2O3-TiC composites with different particle size were fabricated. The addition of TiC into the alumina matrix remarkably improves the mechanical properties and thermal shock resistance. Decreasing grain size can improve the thermal shock resistance, and an increase in density improves it ever further. The critical thermal shock temperature difference (Delta Tc) of an Al2O3 (powder size 0.24 micron)-TiC (powder size 0.32 micron) composite is 100 C higher than that of the monolith. 21 refs.