Ultrahigh-Temperature Ceramic Based on ZrB2–SiC: Preparation and Main Properties

Resumo

Hot pressing of commercially available powders is used to prepare dense ceramic based on ZrB₂ –SiC with different additives (Si₃N₄, TiSi₂, ZrSi₂, MoSi₂). 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^1/2. 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.