Preparation of ZrB2-SiC-C composites using polycarbosilane as preursor

ZrB2-SiC-C Ultra High Temperature Ceramics have been produced by pyrolysis and then hot pressing the mixtures of ZrB2 and polycarbosilane (PCS) powder. The content of PCS was set according to the derived SiC content, which was ranged from 0% to 30% in volume at an interval of 5%. The phase constitutes, microstructures, mechanical properties of the dense materials were characterized by X-ray diffraction, scanning electron microscopy and Vickers indentation technique. It was proved that dense and homogeneous composites could be obtained when SiC content was 15% and 20% in volume with good fracture toughness, but the hardness was lower due to the existence of C.