Improved microstructure and high temperature mechanical properties of C/C–SiC composites by introduction of ZrC nanoparticles

Abstract

ZrC nanoparticles were used to improve the microstructure and mechanical properties of C/C–SiC composites. It was found that the microstructural features and high temperature mechanical properties of C/C–SiC composites were dependent on the ZrC content. Microstructure analysis indicated that the introduction of ZrC nanoparticles effectively improved the distribution homogeneity of SiC matrix. With increasing the ZrC content, the distribution of SiC in the composites gradually transformed from a zonal distribution to a network structure distribution. The influence of ZrC content on the high temperature mechanical properties were investigated at elevated temperatures under ambient atmosphere. It was found that the introduction of ZrC nanoparticles could be an attractive way for improving the mechanical properties by the present processing route. The flexural strengths of all composites at RT increased with increasing the amount of ZrC. The CSZ10 exhibited the highest flexural strength at RT, which was about 196.1 MPa. Comparing with the CSZ0, it increased by 47%. However, at 1000 °C, the CSZ8 composites exhibited the highest flexural strength (55.2 MPa) and a better strength retention (~30%, compared with RT strength). The good strength retention could be attributed to a moderate fiber-matrix bonding strength and improved anti-oxidation resistance which were caused by the homogeneous distribution of SiC matrix.