Ultrahigh-Temperature Ceramic Based on ZrB–SiC: Preparation and Main Properties

Hot pressing of commercially available powders is used to prepare dense ceramic based on ZrB –SiC with different additives (SiN, TiSi, ZrSi, MoSi). The main physicomechanical properties are measured in macro-specimens: ultimate strength in static three-point bending at room temperature 400 – 600 MPa, Vickers microhardness up to 15 GPa, and critical stress intensity factor up to 5.9 MPa·m. Average LTEC, thermal diffusivity, thermal conductivity, and oxidation resistance over a wide temperature range are determined. Altogether the ceramic properties obtained are at the level of published indices.