Study on the oxygen diffusion in the oxide layers of SiBCN ceramics by SIMS.

• The oxide layer of SiBCN can be divided into outer and inner parts under 1300 °C. • The oxygen molecules diffused in SiC through the gaps in lattice, while diffused in SiBCN by substituting the O in SiO 2. • BN(C) phase in SiBCN can slow down the generation rate of gases such as CO, N 2 , NO 2 and B 2 O 3. SiBCN, SiC and SiC-BN ceramics/composites were prepared by mechanical alloyed combined hot-pressing sintering at 1900 °C, and the oxidation kinetics of SiBCN, SiC and SiC-BN were calculated based on the thickness of oxide layers at 1100∼1500 °C. The oxide layer can be divided into outer and inner parts under 1300 °C. At 1100 °C, the oxygen molecules diffused in SiC through the gaps in lattice, while diffused in SiBCN by substituting the O in SiO 2. Moreover, BN(C) phase in SiBCN can slow down the generation rate of gases such as CO, N 2 , NO 2 and B 2 O 3. [ABSTRACT FROM AUTHOR]