Heterogeneous oxidation behavior and kinetic mechanisms of SiBCN ceramic with structure of MA-SiBCN coated by PDCs-SiBCN

In this study, SiBCN ceramics with a structure of three-dimensional PDCs-SBCN network structure coated MASiBCN (MA@PDCs-SiBCN) were fabricated, which significantly improved the sintering activity and oxidation performance. The effect of MA@PDCs-SiBCN structure on oxidation behaviors and kinetics of oxide layer growth of the SiBCN ceramics at 1500 degrees C was investigated, indicating that the significantly improved oxidation resistance is attributed to the different heterogeneous oxidation behaviors, especially in the initial stage. Therefore, the heterogeneous oxidation behaviors and kinetic laws of different phases in MA@PDCs-SiBCN ceramics at different temperature ranges and their effects on structural evolution and oxide layer composition were analyzed by comparison with the MA-SiBCN ceramics. The significantly improved oxidation resistance of MA@PDCsSiBCN ceramics should be attributed to the inhibition of MA@PDCs-SiBCN structure to heterogeneous oxidation, especially the consumption of t-C, and different oxide layer composition generated from microcrystalline structure rather than nanocapsule-like crystalline structure.

Automated summary

In this study, SiBCN ceramics with a special structure were prepared to improve the oxidation resistance. The effect of the structure on oxidation behavior and kinetics was investigated, revealing that the special structure can effectively inhibit heterogeneous oxidation and enhance the oxide layer composition.