Influence of Hot Pressing Temperature and SiC Content on the Microstructure and Mechanical Properties of ZrB2-SiC
The influence of hot pressing temperature and SiC content on the microstructure and mechanical properties of ZrB2-SiC ceramics was investigated. ZrB2 containing 20 volume percent SiC were prepared by hot pressing at 1850, 1900 and 1950°C for 60 min. Fully dense ceramic was obtained after hot pressing at temperature of 1950°C. In addition, the materials with SiC content of 0, 10vol.%, 15 vol.%, 20 vol.% and 30 vol.% hot pressed at 1950°C were also investigated. Results showed that the grain size of the ZrB2 significantly reduced on adding 10vol.% SiC and then decreased slightly with further increasing SiC content, whereas the grain size of SiC exhibited a opposite trend. The flexural strength of ZrB2-SiC ceramics remarkedly increased on adding 10vol.% SiC due to the significant decrease of ZrB2 particle size and then slightly increased with increasing SiC content up to 20vol.%. However, further increasing SiC content led to a reduction of the flexural strength.