Microstructure formation on exposure of silicon carbide surfaces to the partial oxidation of methane

Abstract

Gas-phase silicon-based species, produced on exposure of silicon carbide (SiC) surfaces to the partial oxidation of methane, can be transported away from the site of corrosion to form surface nano- and microstructures. These structures can be divided into two groups, silicon-based structures and silicon/carbon-based structures. Silicon oxide nanowires are the most prevalent of the silicon-based structures, and form on SiC surfaces downstream of the combustion zone. The silicon/carbon-based structures, formed towards the end of the combustion zone, are core–shell heterostructured fibres and take the form of either conical fibres or cross-linked fibre lattices. Low reactive gas concentrations, high temperatures and low methane/oxygen ratios enhance microstructure formation. The effect of gas-phase chemistry and fluid flow on surface behavior is discussed.