Preparation and properties of 3D needle-punched C/ZrC–SiC composites by polymer infiltration and pyrolysis process

Abstract

Three-dimensional (3D) needle-punched C/ZrC–SiC composites were successfully fabricated by infiltration and pyrolysis of a novel liquid ZrC precursor and polycarbosilane (PCS) separately. The effects of PIP cycles of PCS on the microstructures and mechanical property of the composites were studied. The C/ZrC–SiC composite with more PIP cycles of PCS had a high performance in mechanical property due to its higher density. The C/ZrC–SiC composite with 6 PIP cycles of PCS had a flexural strength of 142.4±17.5MPa and a fracture toughness of 7.6±0.3MPam1/2, which was superior to C/ZrC composites with the same total 20 PIP cycles. The ablation behaviors of the C/ZrC–SiC composite were studied using an oxyacetylene torch. The formation of continuous molten ZrO2 layer contributed mainly the high ablation resistance in the center region, while the SiC matrix accounted for the improved oxidation resistance beyond the center and transition regions. Moreover, the ZrC matrix homogeneously distributed in composite can act as a reservoir of the ZrO2 phase, and then supplemented the ZrO2 loss continuously in the whole testing.