Thermal stability and crystallization process of SiBONC ceramics derived from polymeric precursors

SiBONC ceramic precursor was synthesized from raw materials of silicon tetrachloride, phenyle aldehyde, boron trichloride and aniline and subsequently transformed into ceramic nano-powder by pyrolysis up to 1000°C. And then the nano-powder was hot-pressed to form the SiBONC ceramics. The decomposition properties and crystallization of amorphous precursor-derived SiBONC ceramics and powders were investigated in gas pressure furnace. The bulk ceramics and powder could keep amorphous state even at 1700°C, and the crystallization temperature was above 1800°C, the main phase was SiC and some BN, the mass loss rate was 4% at 1900°C. Doping of B, C, N can raise the thermal stability and crystallization temperature, at the same time, the high-temperature mechanical properties can be also raised because of precipitating of the nanometer SiC particles.