Heterogeneous oxidation involving different atomic clusters in sintering-free amorphous SiBCN ceramic with MA@PDC-SiBCN structure

Amorphous SiBCN monoliths featuring a structure of three-dimensional PDC-SiBCN network encapsulating MA-SiBCN nanoparticles (MA@PDC-SiBCN), were prepared without the need for sintering densification (>1800 °C), enabling preparation of dense ceramics at a much lower temperature (1100 °C). The continuous PDC-SiBCN network effectively inhibits oxygen diffusion, reducing the mass loss from B–C–N cluster oxidation and mass gain from silicon-containing clusters by 51.5 % and 86.9 %, respectively. Besides, the phase-separation coupled heterogeneous oxidation behaviors and kinetics of different atomic clusters in MA@PDC-SiBCN ceramic during non-isothermal oxidation up to 1500 °C were investigated. Finally, the evolution of the different atomic clusters within the oxide layer during the heterogeneous oxidation process was analyzed to elucidate the micro-mechanisms behind the enhanced oxidation resistance.