Effect of precoated carbon layer on microstructure and anti‐erosion properties of SiC coating for 2D‐C/C composites

Abstract

To improve the erosion resistant of carbon‐carbon composites, an SiC coating was synthesized on carbon‐carbon composites by the in situ reaction method. They are firstly coated with carbon layer by slurry, and then SiC coatings are obtained by chemical vapor reaction. The effects of precoated carbon layer on the microstructure and anti‐erosion properties of SiC‐coated C‐C composites were studied and characterized. The thickness of the SiC coating increased with the increase in the precoated carbon layer thickness. The different thickness of carbon layer affects hardness of the SiC coatings, resulting in diverse erosion resistance of the coatings. The SiC coating prepared with moderate thickness of precoated carbon layer exhibits the best erosion resistance, and show better resistance at an impact angle of 30° than 90°. The eroded surface revealed that coating cracking and brittle fracture, fiber‐matrix debonding, fiber breakage, and material removal, and the additional microcutting and microploughing at oblique impact angle are the major erosion mechanism of SiC coating for C/C composites.

Preparation and ablation resistance of carbon fiber with yttrium silicate coating

“…Some researchers have conducted high-temperaturestabilized ceramic materials as surface coatings for carbon fibers. Literature on several single coatings has been published, such as SiC, 8,9 SiOC, 10 SiO 2, 11 ZrO 2, 12,13 and TiC. 14 In addition, composite coatings have been widely reported.…”

“…Ratnayake et al 17 prepared boron-doped yttriastabilized ZrO 2 surface coatings on polyacrylonitrile-based carbon fibers and examined the thermal behavior. Typical preparation processes for these coatings include chemical vapor deposition, 9 chemical vapor infiltration, 14 precursor infiltration and pyrolysis, 8,10 and sol-gel 11,12,[15][16][17] methods. In contrast, the sol-gel method requires a straightforward preparation process, low cost, and high suitability for coating on different substrates, which is a potential method for development.…”