Microstructural X-Ray Studies of Silicon Nitride-Based Composite Ceramic Material

Samples of silicon nitride-based composite ceramic material were produced using a developed technology, using hot casting followed by reaction sintering, as well as “gentle” thermal-oxidative surface preparation to enhance the material’s heat resistance, thereby ensuring the required characteristics of products made from these materials. A microstructural study of the samples, with and without additional oxidation, was conducted using scanning electron microscopy and energy-dispersive secondary and backscattered electron analysis. A detailed structural analysis revealed that the matrix is primarily composed of sintered grains of silicon nitride Si3N4, interspersed with silicon oxynitride Si2N2O. Modification of the silicon-oxygen network with aluminum cations increases its viscosity, which positively impacts its resistance to mechanical entrainment in high-speed gas flows.