Heat‐Resistant Silicon Carbide with Aluminum Nitride and Erbium Oxide

Abstract

Fully dense SiC ceramics with high strength at high temperature were obtained by hot‐pressing and subsequent annealing under pressure, with AlN and Er2O3 as sintering additives. The ceramics had a self‐reinforced microstructure consisting of elongated SiC grains and a grain‐boundary glassy phase. The strength of these ceramics was ∼550 MPa at 1600°C, and the fracture toughness was ∼6 MPa·m1/2 at room temperature. The beneficial effect of the new additive composition on high‐temperature strength might be attributable to the introduction of aluminum from the liquid composition into the SiC lattice, resulting in a refractive grain‐boundary glassy phase.