Stitched carbon fiber cloth reinforced zirconium carbide composite (C/ZrC) was prepared by polymer infiltration and pyrolysis (PIP) process. C/ZrC-SiC composite was obtained by further introduction of SiC with PIP process in order to improve anti-oxidation property. The results show that 1.9vol% SiC addition improves the mechanical and anti-oxidation properties of C/ZrC composite. The flexural strength of C/ZrC is 247.9MPa, while that of C/ZrC-SiC is 273.1MPa. After oxidation in a muffle furnace at 1200°C for 30 minutes, the mass loss rate was reduced from 30.6% (C/ZrC) to 20.1% (C/ZrC-SiC), and the flexural strength and elastic modulus of C/ZrC were 56.7MPa and 5.7GPa, respectively, while those of C/ZrC-SiC were 122.9MPa and 17.2GPa, respectively.

Aerogel composites were prepared by immersing ceramic fiber into silica aerogel precursor via supercritical fluid drying. The mechanical behavior of silica aerogel composites was investigated with shrinkage, tension, bending and compression. The influences of fiber volume fraction, aerogel density and heat treatment were examined. After reinforced by ceramic fiber, the shrinkage of aerogel and aerogel-fiber composites was retarded obviously. The mechanical property of aerogel-fiber composites increased first and then decreased with increasing fiber volume fraction from 5.8% to 11.5%. For a given fiber volume fraction, the mechanical strength enhanced with increasing aerogel density. In addition, the mechanical property of aerogel composites did not decrease but increased after heat treatment at 600°C.

No abstract

Sino Fibers Reinforced BN Wave-Transparent Composites (SiNOf/BN) Were Fabricated through Precursor Infiltration and Pyrolysis (PIP) Method Using Borazine as Precursor. The Effect of Pyrolysis Temperature on the Densification Behavior, Microstructures, Mechanical Properties and Dielectric Properties of the Composites Was Investigated. The Results Suggest that with the Increase of the Pyrolysis Temperature from 800 °C to 1000 °C, the Density, Mechanical Properties and Dielectric Constant of the Composites Are Increased, but the Infiltration Efficiency Varies Little. At the Pyrolysis Temperature of 1000 °C, the Density of SiNOf/BN Composites is 1.84 g∙cm-3 and the Flexural Strength and Elastic Modulus Are 148.2 MPa and 26.2 GPa Respectively. The Dielectric Properties, Including Dielectric Constant of 3-4 and Dielectric Loss Angle Tangent of below 7×10-3, Obtained at Three Different Temperatures Are Excellent for the SiNOf/BN Composites Applied as Wave-Transparent Materials.

C/C-SiC composites were prepared by reactive melt infiltration process at different temperatures. The composition, microstructures and mechanical properties of the composites were investigated. The results showed that infiltration temperature could affect composite’s properties through regulating the chemical composition and interfacial bonding strength of the composites. The C/C-SiC composite prepared at 1650°C exhibited the relatively highest performance with density of 2.24 g·cm-3 and SiC content of 31.44 vol.%. The flexural strength and the fracture toughness were 238MPa and 10.04 MPa·m1/2, respectively.