Dense, pure SiC monoliths with excellent oxidation resistance sintered at low temperatures and high pressures

Abstract

Pure SiC ceramic monoliths were sintered at 1100–1200°C and 5GPa coupled with mechanically alloying. The mechanically alloyed SiC powders are nearly completely amorphous containing a small quantity of 2nm-sized crystallites. The resulting monoliths consist of amorphous and 3C–SiC nanocrystallites (<5nm), and offer relative densities ≥93.0%, nanohardnesses ≥34.0GPa and elastic moduli ≥378GPa. In the flowing air at 1500°C, they undergo minimal mass change indicative of excellent oxidation resistance.