The effects of multiphase composition on structure and mechanical properties of ZrO2/Si–C–O ceramic fibers by sol-gel process

High temperature thermally stable fiber materials with flexibility are expected to be applicable to severe conditions. In this article, ZrO2/Si–C–O ceramic fibers have been synthesized by the sol-gel process combined with the electrospinning technique. We focus on the changes of composition, structure and morphology with the increasing heat treatment temperature. More importantly, the effects of ZrO2 crystalline phase transformation on mechanical property of ZrO2/Si–C–O ceramic fibers have been investigated. The results show that the increased temperature can lead to an increase of the fiber diameter and grain size, as well as the transformation of ZrO2 phase. It is also found that the ZrO2/Si–C–O ceramic fibers possess refined crystalline grain and improved mechanical properties at a heat treatment temperature of 800 °C, which is mainly due to the fact that the amorphous Si–C–O phase containing free carbon facilitates the refinement of the crystalline grain, and the ZrO2 in the tetragonal structure improves the flexibility of ceramic fibers. Furthermore, the obtained fibers exhibit excellent thermal stability up to 1300 °C, therefore they have broad application prospect in high temperature environment.