In situ synthesis of nonoxide-boron nitride (Nobn) composites

In situ process is advantageous for obtaining better ceramic composites. In this work the reactions and processing of in situ nonoxide-boron nitride (Nobn) composites include SiC-BN, Si 3 N 4 -BN, SiAION-BN, AlN-BN and AlON-BN composites were discussed. For obtaining these BN composites, novel in situ reactions were proposed. Reaction mechanisms and the factors, which affect the reaction processes, were investigated and discussed according to the results of XRD and TG-MS analysis. It was pointed out that the furnace atmospheres and pressure demonstrated obvious effect on the reaction process. Finally, in situ Nobn composites were prepared by hot pressing or pressureless sintering according to the proposed in situ reactions. In some case net-shape sintering could be realized.