Microstructure and properties of SiBCN/SiBCN mini-composites prepared by the precursor infiltration and the pyrolysis process

SiBCN fiber reinforced SiBCN matrix mini-composites (SiBCN/SiBCN) as a new type of the ceramic matrix composite were fabricated by precursor infiltration and pyrolysis (PIP) process. Various degumming methods for continuous SiBCN fibers resulted in different properties and surface conditions, further affecting the interfacial bonding strength (IFBS) and mechanical properties of the composites. The relationship between fiber degumming modes, fiber states, and properties of composites was discussed and the strengthening mechanisms of the SiBCN/SiBCN mini-composites were explored. With a degumming treatment of N,N-dimethylformamide (DMF) soaking, the flexural strength and modulus of mini-SiBCN/SiBCN composites achieved 508 +/- 68 MPa and 79 +/- 12 GPa, respectively. The novel strengthening mechanism of the microcrystalline SiBCN fiber reinforced microcrystalline SiBCN matrix composites will enrich and be helpful to understand the strengthening and toughening mechanisms of ceramic matrix composites.