Vapour Growth of Micro-Coiled Ceramic Fibers and their Properties

Micro-coiled fibers of carbon, Sic, Si N Tic, ZrC and Hf C were prepared by a metal-impurity activa?e%'chemical vapor deposition or vapour phase metallizing of the coiled carbon fibers. The growth conditions, morphology, growth mechanism and some properties were examined. The double-coiled carbon fibers were prepared using acetylene as a carbon source and various powders or plates of transition metals, metal carbides, MoS2, Ti203, and Ni single crystal plate as a catalyst at 650-850°C. The triple-coiled Sic fibers were prepared using coked rice husks and/or SiO as a Si-source and Ni, Cr or Fe as a catalyst at 1400-1500°C. The double-coiled Tic fibers were prepared by the PC1 activated CVD process on a graphite substrate using a Pt+Si or $d+~i mixed catalyst at 1050-1250°C.