Densification and optimization of SiCf/SiC composites by low-temperature NITE process

Dense nano-infiltration and transient eutectic phase (NITE)-SiC f /SiC composites are prepared through low-temperature sintering technology at 1650°C. The densification of SiC matrix, as well as effects of BN interphase thickness and fiber volume fraction on the morphology and mechanical properties of SiC f /SiC composites are investigated. AlN‒Y 2 O 3 ‒SiO 2 can fully wet SiC at 1650°C and the matrix of SiC f /SiC composites can be densified via 40 wt% sintering aids. A thick BN interphase layer can reduce stress on the fiber and the interphase in stress concentration regions, but may exacerbate stress concentration in non-concentrated regions. A moderate fiber volume fraction is necessary to balance the content and damage of reinforcement to obtain SiC f /SiC composites with high mechanical property. The optimum volume density, open porosity, and flexural strength of SiC f /SiC composites is 2.98 ± 0.05 g/cm 3 , 3.5 ± 1.7%, and 430 ± 34.2 MPa. This work can provide conduction for fabrication and optimization of low-temperature sintering NITE-SiC f /SiC composites.