SiC Coatings Fabricated by Chemical Vapor Reaction on Graphite

The improvement of the oxidation resistance of graphite, which is the key materials for construction of high temperature gas-cooled reactor(HTR), can further improve the safety of HTR. SiC coatings were fabricated by chemical vapor reaction (CVR) on HTR fuel element matrix graphite, and the structure characteristics of SiC coatings were analyzed with XRD, Raman spectra and SEM. The coatings with only β-SiC was obtained and the ideal gradual transition layers existed at the interface between the coatings and substrates. There existed some small pore in SiC coatings fabricated by CVR, which made the coatings only by CVR obtaining poor oxidation resistance; but uniform SiC coatings with excellent oxidation resistance at low cost could be obtained by combining CVR and other fabrication methods.