Preparation and Ablation Performance of BN Fiber Fabrics Reinforced Nitrides Composites

摘要

High-performance three-dimensional boron nitride fiber reinforced silicon nitride (BN_f/Si_3N_4) composites were prepared by the infiltration and pyrolysis (PIP) process using BN fiber fabrics as the reinforcing body and excellent nitride organic precursor (Perhydropolysilazane, PHPS) as the Impregnated liquid. The ablation resistance of the composite was evaluated by plasma jet ablation test in air. The results show that a uniform and dense interface layer is formed on the fiber surface, with thickness is about 100 nm, and the XRD test shows that it is hexagonal BN (h-BN). The density of the composite reaches more than 1.72 g·cm~(-3) and the bending strength is more than 80 MPa. Under the condition of plasma jet ablation test at 2000°C/200 s, the mass ablation rate is 3.32× 10~(-4) g/s, the linear ablation rate is 4.78×10~(-3) mm/s. The prepared materials have excellent resistance to high temperature ablation and are expected to be used in the field of high temperature microwave transparent such as high mach missile radome, antenna window and so on.