Carbon/ceramic microcomposites, preparation and properties

Abstract Carbon–carbon and carbon–ceramic microcomposites were molded by using thermoplastic polyimide coated carbon and ceramic powders. The effect of particle size powders and different processes of hot pressing were examined. A 53 MPa flexural strength and a 10 GPa flexural modulus were obtained for 2.15 g/cc density microcomposites. Thermo-oxidative stability of carbon microcomposites with three combinations of B 4 C/SiC additives were compared with original carbon–carbon microcomposites. The oxidative stability of the carbon/B 4 C/SiC composites was extended up to 1000°C. After exposure to flowing air at 700°C for 100 h, the weight lost of the carbon–ceramic composites was only 4%, attributed to boron oxide evaporation. There is a degradation of the mechanical and physical properties of carbon–carbon and carbon–ceramic composites after carbonization and graphitization. This degradation is slowed down by B 4 C/SiC additives.