Development of Nanostructured SiC Coating on Advanced Carbon Materials and Their Applications
Search this Article
Diamond particles and multi-walled carbon nanotubes (MWCNTs) were coated with a nanometer-sized SiC polycrystalline layer by the reaction of SiO(g) and CO(g). The growth mechanism of SiC and the oxidation resistance of the SiC-coated carbon materials were studied. The growth process of the SiC layer can be separated into two steps. In the first step, a thin layer of SiC is formed due to the reaction between SiO vapor and carbon materials. In the second step, nanometer sized SiC granules are deposited on the SiC layer by the reaction between SiO vapor and CO. The oxidation resistance of the carbon materials was improved by the SiC coating. Oxidation of the SiC-coated diamond particles began at 950℃, which is 400℃ higher than that of uncoated diamond. MWCNTs were oxidized completely in air at 650℃ for 60min. However, about 90 mass % of the SiC-coated MWCNTs remained after the same oxidation test. Dense composites reinforced by the SiC-coated carbon materials were successfully fabricated using a pulsed electric current sintering. The composites showed excellent mechanical properties compared to the monolithic materials and the composites reinforced by uncoated carbon materials.
- Transactions of JWRI
Transactions of JWRI 33(2), 103-113, 2004-12