Microstructure and mechanical properties of SPS sintered Al2O3–ZrO2 (3Y)–SiC ceramic composites

Al 2 O 3 –ZrO 2 (3Y)–SiC ceramic composites were prepared by spark plasma sintering in vacuum under 40 MPa of uniaxial compression between 1300 °C and 1400 °C. The effect of nano-size SiC and sintering temperature on the microstructure and mechanical properties of ceramic composites were investigated. The results showed that SiC particles was uniformly distributed in the composite, mainly within the matrix grains. Sintering temperature and SiC particles caused the shape of alumina grains to be columnar. The flexural strength of 22.3 vol% Al 2 O 3 -57.7 vol% ZrO 2 -20 vol% SiC sintered at 1350 °C composites was 1081 MPa, fracture toughness was 15.18 MPa m 1/2 and hardness was 16.42 GPa. The addition of SiC particles leads to grain boundary strengthening, and the change of fracture mode and cracks deflection and bridging are considered to be the main reasons for the increase in material fracture toughness.