Electrical and Mechanical Properties of ZrB2-Based Composite Ceramic

Abstract

The ZrB2-SiC composite ceramic was prepared using Al2O3 and Y2O3 as additives through pressureless sintering under 1800°C. The electrical and mechanical properties were studied with the different mass ratio of ZrB2 and SiC. The microstructure and phase transformation of the ZrB2-SiC composites ceramic were characterized by scanning electron microscopy. Results show that the densities of the samples are decreased with the decrease of the mass ratio of ZrB2 and SiC while the resistivities are increased. When the mass ratio of ZrB2 and SiC is 4 the resistivity reaches 14μΩ•mm while the density is 4.85g/cm3. When the mass ratio of ZrB2 and SiC is13:7, the flexural strength reaches the max value and toughness reaches the minimum value. The flexural strength reaches 233Mpa and the toughness reaches 4.51 Mpa• m 1/2. The changes of the properties of the ceramic were analyzed through the microstructure and the conduction mechanism was studied.