Microstructures and mechanical properties of Cf/ZrB2-SiC composite fabricated by nano slurry brushing combined with low-temperature hot pressing

Abstract

The Cf/ZrB2-SiC composite was successfully fabricated via brushing nano ZrB2-SiC slurry followed by low-temperature hot pressing technique, in which the UHTC phases were uniformly introduced into intrafascicular space of the subdivided fiber bundles. The fabricated composite exhibited a non-brittle fracture behavior and excellent mechanical properties with a high work of fracture of 1338 J/m2, one order of magnitude higher than that of the ZrB2-SiC ceramic, which was attributed to the hybrid toughening mechanisms such as crack deflection, fiber bridging, fiber pull-out and crack branching. The fiber/matrix interfaces were analyzed by the high resolution transmission electron microscopy, and no obvious chemical reaction was detected, suggesting the degradation of carbon fiber was effectively inhibited. Moreover, the Cf/ZrB2-SiC composite showed a good thermal shock resistance with a thermal shock temperature difference of 764 °C, almost twice those of the ZrB2-SiC ceramic. This work provides a facile and effective approach to fabricate high-performance continuous carbon fiber reinforced ceramic composites with uniform component distribution.