Application of Composite Ceramics for Fabrication of Components with High Heat Resistance

This study proposes a technique for fabrication of highly thermoresistant components from a silicon nitride-based composite ceramic material using hot casting followed by reaction sintering. Methods for increasing the heat resistance of the components have also been developed by incorporating ethyl silicate impregnation and “gentle” preliminary oxidation at 1480°C for 5 h. The resulting composite material, consisting of 35% Si3N4 + 65% Al2O3, exhibits high heat resistance: at least 10 cooling cycles by immersion in water (20°C) after heating to 1200°C, and high heat resistance in oxidizing environments: long-term at 1500°C and short-term at 1700°C. Positive results have demonstrated the potential for use of the developed composite in heat-loaded aircraft components.