In situ growth of dense SiC nanowires on structural defined carbon fibers without sacrificing flexibility

Abstract

A convenient thermal evaporation method was developed to grow SiC nanowires (SiCNWs) uniformly into carbon fiber bundles by using Si/SiO2 mixtures as silicon source. The effect of the exhaust position in reaction vessel and the additional compensatory carbon source on the growth of SiC nanowires and the mechanical property of carbon fibers was investigated. The results show that the position for the escaping of reactant gases and the compensatory carbon have a remarkable influence on the uniform growth of SiC nanowires in carbon fibers bundles and the tensile strength of carbon fibers. Adjusting the exhaust position from top to bottom of graphite crucible could obtain a large scale of high quality SiC nanowires grown uniformly in carbon fiber bundles, but these carbon fibers became brittle. The further modification by adding compensatory carbon source in the synthesis procedure successfully realized the uniform synthesis of massive high quality SiC nanowires and preserved the carbon fibers’ flexibility performance simultaneously. It indicated that the changing of exhaust position combined with the addition of appropriate proportion of compensatory carbon can build a suitable surrounding environment, extremely promoting the uniform and massive growth of high quality SiC nanowires on carbon fibers and effectively protecting carbon fibers from erosion.