SiC fibre by chemical vapour deposition on tungsten filament

A CVD system for the production of continuous SiC fibre was set up. The process of SiC coating on 19 µ m diameter tungsten substrate was studied. Methyl trichloro silane (CH3SiCl3) and hydrogen reactants were used. Effect of substrate temperature (1300–1500°C) and concentration of reactants on the formation of SiC coating were studied. SiC coatings of negligible thickness were formed at very low flow rates of hydrogen (5 × 10−5 m3/min) and CH3SiCl3 (1.0 × 10−4 m3/min of Ar). Uneven coatings and brittle fibres were formed atvery high concentrations of CH3SiCl3 (6 × 10−4 m3/min of Ar). The flow rates of CH3SiCl3 and hydrogen were adjusted to get SiC fibre with smooth surface. The structure and morphology of SiC fibres were evaluated.