Progress of a novel amorphous and nanostructured Si-B-C-N ceramic and its matrix composites prepared by an inorganic processing route

Abstract

The development of novel, high-temperature structural and multifunctional heat-resistant materials for service under high-temperature oxidation, severe thermal shock, ablation by combustion gas flow, and other harsh conditions has become one of the most pressing needs in the aerospace industry. Amorphous and nanocrystalline Si-B-C-N ceramic and its matrix composites have great potential applications in the fields of high-temperature structural and multifunctional heat-resistant ceramics because of their special structures and outstanding high-temperature properties. The preparation of dense Si-B-C-N ceramic bulks is greatly limited by the organic polymer precursor pyrolyzing method (organic processing route). Mechanical alloying and post-hot-pressing technologies (inorganic processing route) using inorganic powders as the raw materials were pioneered by researchers from the Institute of Advanced Ceramics at Harbin Institute of Technology about 10 years ago. The inorganic processing route, which is very simple and effective in the preparation of materials with uniform microstructures and excellent properties, has been used to obtain dense Si-B-C-N ceramic bulks and structural components resistant to high temperatures. The inorganic processing route has become an indispensable complement to the organic processing route and has resulted in improved and enriched experimental data and understanding of Si-B-C-N ceramics. Current research achievements in the field of SiBCN ceramics and their matrix composites obtained by the inorganic processing route (including microstructural characteristics, evolution laws, mechanical and thermophysical properties, the resistance to oxidation, thermal shock and ablation, and related mechanisms) are summarized and future trends are predicted.