Effect of short fiber content on mechanical properties of C/C-SiC composites prepared by WP-LSI

C/C-SiC composite strengthened with short carbon fiber of volume fraction of 20%, 25% and 30%respectively were prepared by Warm Compressing-Liquid Silicon Infiltration(WC-LSI). The effect of fiber content on the mechanical properties of C/C-SiC was studied and compared with similar product on the market. The results show that, with increasing the carbon fiber content from 20% to 30%, the open porosity decreases, flexure strength and compressive strength of the composite increase. The density and open porosity of the C/C-SiC composite with carbon fiber content of 30% are 2.00 g/cm3 and 2.88%, respectively, the bending and vertical compressive strength are 104.63 MPa and 167.99 MPa, which are 86.04% and 44.76% higher than that of the C/C-SiC composite with carbon fiber of20%, and are 2.03% and 11.99% higher than that of foreign sample. The failure process changes from pseudo plastic destruction to brittle failure with increasing carbon fiber content.