Vapour Growth of Micro-Coiled Ceramic Fibers and their Properties

Abstract

Micro-coiled fibers of carbon, SiC, Si 3 N 4 , TiC, ZrC and HfC were prepared by a metal-impurity activated 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, MoS 2 , Ti 2 O 3 , 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 3 activated CVD process on a graphite substrate using a Pt+Si or Pd+Si mixed catalyst at 1050-1250°C.