Microstructural evolution and interfacial reaction mechanisms of nano-amorphous SiBCN modified SiC–Si3N4 ceramic

The amorphous nano-SiBCN phase was used to control the microstructure of SiC–Si3N4 composite ceramics via in situ reactive spark plasma sintering. Two distinct reaction setups were established, utilizing B4C and B2O3 as the respective sources of boron. Both experimental data and thermodynamic simulations were employed to investigate the sintering behavior, phase composition, and microstructural evolution of the ceramic composites. Accordingly, the integration of B2O3, as opposed to B4C, markedly improved the efficiency of the solid-phase reaction. This facilitated the formation of the amorphous SiBCN phase through exothermic oxygen reduction. Simultaneously, a comprehensive analysis of the atomic structure and interfacial characteristics of the amorphous SiBCN phase was investigated. This research offers an efficient approach for advancing the development of high-performance amorphous-doped ceramic matrix composites.