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 B x C phase and growth of SiC gains. At the initial stage of oxidation, surface B x C and BN(C) are prior to SiC generating B 2 O 3 . As time progresses, SiC oxidizes to SiO 2 further reacted with B 2 O 3 forming stable SiO 2 -B 2 O 3 binary melt or borosilicate. Boron-enhanced SiC oxidation occurs immediately with the rapid consumption of BN(C), B x C and loss of B 2 O 3 from borosilicate decomposition, thereby promoting oxidation rate. Substantial SiC and BN(C) in amorphous SiO 2 for transition layer is the main structure feature.