Fabrication of high performance silicon oxynitride fibers reinforced boron nitride composites via borazine precursor infiltration and heating

SiNOf/BN composites with silicon oxynitride fibers in a boron nitride matrix were prepared by precursor infiltration and heating (PIH) using borazine as precursor. The densification, microstructure and mechanical properties of the composites were studied. The density of SiNOf/BN composites increased rapidly with PIH cycles. The composites prepared by two and three PIH cycles are highly tolerant of damage due to the high retained fiber strength, dense matrix and moderate bonded fiber/matrix interface. Desirable high temperature mechanical properties of SiNOf/BN composites were also obtained. The residual flexural strength and elastic modulus of composites at 1300 °C were 131.0 MPa and 26.6 GPa, respectively.