Preparation of C/SiBCN composites by precursor infiltration and pyrolysis using a novel precursor

A novel polyborosilazane (PBSZ) precursor was synthesized via single source precursor route, in which B existed in the form of B–N hexatomic ring in the main chain. The conversion from precursor to ceramic was completed at 800 °C with the ceramic yield of 48.5 wt%. The pyrolyzed SiBCN ceramics can remain amorphous up to 1600 °C. In view of above-mentioned properties, the polymer was employed to fabricate carbon fiber reinforced SiBCN matrix composites (C/SiBCN composites) via precursor infiltration and pyrolysis. The composites were dense with a density of 1.61 g cm−3 and an open porosity of 6.05% due to the effective infiltration of the precursor and an improved pyrolysis process. And the flexural strength and modulus were 324 MPa and 56.9 GPa, respectively.