Ablation Performance and Surface Texture of the Nitride Composites Reinforced by the Braided Silica Fibers

Abstract

Braided silica fibers reinforced nitride composite (SFRN), which was prepared by the polymeric precursor infiltration and pyrolysis (PIP) process with the precursor polyborosilazane (PSBZ), was a new typed microwave transparent material with high mechanical and ablation resistance performance for high-temperature application. The thermal ablation performance of the SFRN was evaluated by the ablation equipment with the kerosene and liquid oxygen as the heating source. The ablation surface texture of the SFRN including macrostructure and roughness were measured by Three-dimensional Macrostructure and Contour Scale System (TMCSS). Results showed that there are no concurrent observation of thermal delaminations or cracks and the specimen remains intact. The SFRN has an excellent thermal shock resistance and good ablation resistance with the linear recession rate of 0.038mm/s. The ablation surface texture of the SFRN can be well illuminated by the TMCSS. And the ablation performance will be improved by enhancing material density and homogeneous intertextures.

Slip-Cast Fused Silica Radomes for Hypervelocity Vehicles: Advantages, Challenges, and Fabrication Techniques

“…The various methods and additives utilized so far for enhancing the strength of the fused silica ceramics are summarized in Table 12. The fused-silica composites produced so far are nano-sized silica-silica [70], silica fibers (SiO 2f ) reinforcedsilica [8,82], 3D SiO 2f -SiO 2 [80,83], 2.5D braided silica fibers reinforced nitride (SFRN) [84], silicon nitride (Si 3 N 4 )-doped silica [85], air-oxidized silica and Si 3 N 4 [86], zirconia (ZrO 2 ) doped silica [34], alumina doped silica [87], β-Si 4 Al 2 O 2 N 6silica [10,88,89], and BN-silica [44][45][46][47][48]90] as listed in Table 12 [1,2,4,5,36,61]. Various dopants were also added to confer different properties to fused silica ceramics consolidated by several techniques [1,2].…”