A direct chemical vapor infiltration route for a carbon nanotube/silicon carbide thermal protection system

Sandwich-structured carbon nanotube/silicon carbide (CNT/SiC) sponges were fabricated by direct chemical vapor infiltration (CVI) of SiC matrix into the inner network of CNT sponges without altering the original sponge morphology. The thermal conductivity of the sandwich-structured material from 25 °C to 1200 °C was established in the range of 2.3-4.3 W/mK range. The values were much lower than the pure SiC, which indicates that the material can efficiently dissipate heat along the SiC coating. Based on the design of the sandwich structure produced by direct CVI process, large fiber preforms combined with one-dimensional nano-materials that aid the reduction of surface pore size will be an inspired idea for the design of sandwich-structured large fiber composites.