Fabrication of practically pure Si2N2O ceramic with high performance from amorphous BN surface modified nano-sized Si3N4 powders

In this study, amorphous nano-sized Si3N4 powders were surface modified by BN. Then a stable and dense Si2N2O ceramic was fabricated using the BN surface modified powders, rather than Si2N2O-Si3N4 composites usually prepared from nano-sized Si3N4 powders without surface modification. The effect of BN surface modification on phase transformation, microstructure and mechanical properties were also investigated. Si2N2O ceramics obtained by means of the present method have no residual Si, crystal SiO2 and other oxide additives, which are usually produced by other methods and may seriously influence high-temperature structural and functional applications of Si2N2O ceramics.