Preparation and properties of ZrB₂SiC porous ceramics by spark plasma sintering

ZrB₂SiC porous ceramics with different porosities were prepared by spark plasma sintering. The effects of temperature and pressure on the porosity and mechanical properties were studied. The properties of samples after oxidation at 1773 K were also investigated. The sample sintered at 2073 K for 5 min without pressure showed better comprehensive performance. The porosity, flexural strength and fracture toughness were 38.6%, 108.6 MPa and 1.7 MPa·m¹/², respectively. In contrast, the flexural strength of ZS1 (1973 K, 0 MPa, 5 min), ZS2 (2073 K, 0 MPa, 5 min) and ZS3 (1973 K, 10 MPa, 5 min) were remarkably improved after oxidation, reached 97.2, 166.4, 200.9 MPa, respectively. After oxidation, the fracture toughness of ZS1, ZS2 and ZS3 were 2.57, 2.34 and 2.63 MPa·m¹/², respectively. The ZrB₂SiC porous ceramics fabricated in this paper will have considerable application in the composite material field.