Effects of boron addition on the high temperature oxidation resistance of dense sSiBCN monoliths at 1500 °C

The high-temperature oxidation behavior of various boron addition SiBCN monoliths has been explored. Boron addition promotes the formation of new BxC phase and growth of SiC gains. At the initial stage of oxidation, surface BxC and BN(C) are prior to SiC generating B2O3. As time progresses, SiC oxidizes to SiO2 further reacted with B2O3 forming stable SiO2-B2O3 binary melt or borosilicate. Boron-enhanced SiC oxidation occurs immediately with the rapid consumption of BN(C), BxC and loss of B2O3 from borosilicate decomposition, thereby promoting oxidation rate. Substantial SiC and BN(C) in amorphous SiO2 for transition layer is the main structure feature.