Synthesis of biomorphic SiC fabric ceramic from pre-processed ramie fibres

摘要

Biomorphic SiC fabric ceramic was synthesised by in situ reactive molten silicon infiltration process using artificial ramie fibres' template, phenolic resin, and silicon. The phase compositions, microstructure, and physical characteristics of the biomorphic fabric ceramic were characterised and tested. The results show that the final ceramic retains the ramie fabric structure, and presents duplex microstructure including biomorphic SiC fibres and network SiC ceramic around the biomorphic fibres. This biomorphic SiC fabric ceramic is constituted by 95.8% of SiC, has a low density of 1.02 g cm(-3) and a high porosity of 63.7%, and shows low linear shrinkages and better electrical resistivity along the fibre axis. The uniform and fine SiC particles with the size of similar to 4 mu m indicate that the reaction-formation mechanism is the dissolution of carbon and the precipitation of SiC, without a second precipitation.