Dense amorphous Si₂BC_1-4N monoliths resistant to high-temperature oxidation for hypersonic vehicle

Dense amorphous Si₂BC_1-4N monoliths were subjected to aggressive environments at high-temperatures to explore the oxide scale microstructure and growth kinetics. The effects of high-pressure sintering and crystallization on oxidation resistance were studied in detail. Dense amorphous Si₂BC_1-4N monoliths oxidize according to a parabolic rate law or linear equation, depend on the carbon content. Oxidation first attacks at the outermost surfaces of amorphous phases, subsequently proceeds at the interfaces of the crystallized nuclei and neighboring amorphous phases. High-temperature oxidation induces nucleation and thermo-oxidative coupling promotes the nucleation and growth of the nanocrystals.