Significant influence of Al2O3 on the flexural properties of C/C composites

C/C composites with high flexural strength were prepared by introducing aluminium trioxide (Al2O3) into 2D needle-punched carbon felts before densification. The results showed that the flexural strength of the obtained C/C- Al2O3 composites (1.78 g/cm3) was up to 321.00 MPa loading in X and 345.41 MPa loading in Z, which was improved by 87.7% and 113.7% comparing with that of pure C/C composites (1.81 g/cm3), respectively. And the flexural strength decreased a little when the C/C-Al2O3 composites were heat-treated under 1600 °C. However, the flexural strength happened destructive reduction when heat treatment temperature increased to 2100 °C, because the formation of Al4C3 influence the microstructure of C/C-Al2O3 composites significantly.