Reaction Synthesis of Ceramic Composites Containing In Situ Formed Boron Nitride as Dispersed Phase

摘要

Various nonoxide-boron nitride composites (NOBNs) and oxide-boron nitride composites (OXBNs) are synthesized based on the proposed reactions, in this paper the reactions for preparing silicon carbide-boron nitride (SiC-BN) and aluminum nitride-boron nitride (AlN-BN) composites are emphasized. Si-B-C-N ceramics with ultrahigh-temperature property might be produced from inorganic precursors, such as Si{sub}3N{sub}4, SiC, B{sub}4C, B and C. In addition, microcomposite or nanocomposite of SiC/c-BN might be synthesized based on the proposed reaction if ultrahigh pressure is applied during the reaction process. On the other hand, the nitridation process of AlB{sub}2 is divided into two steps and full nitridation can be realized by controlling the nitridation parameters including temperature, nitrogen atmosphere pressure and time.