Ultra-High-Temperature Ceramics Based on HfB2 – 30% SiC: Production and Basic Properties

Dense HfB 2 – 30 vol.% SiC ceramics were obtained from commercially available powders by the hot-pressing method. Their basic physicomechanical properties were measured: the flexural strength at room temperature was 300 – 700 MPa, the Vickers microhardness reached 20 GPa, the critical stress intensity factor was up to 5.9 MPa·m 1/2 . Thermal expansion and resistance to oxidation were measured in a wide temperature range.