Mechanical and tribological properties of C/C-SiC ceramic composites with different preforms

The C/C-SiC composites were fabricated by the liquid silicon infiltration method. The mechanical and tribological properties of C/C-SiC composites were assessed and compared based on different C/C densities and the carbon fiber textile architecture. The results demonstrated that the bending and shear strengths of C/C-SiC were lower than those of C/C composites, which resulted from the carbon fibers being corroded during the process of infiltration of liquid silicon. In contrast to C/C composites, the compressive strength of C/C-SiC exhibited higher values due to the presence of SiC ceramics. Moreover, the mechanical strength of C/C composites increased gradually with the increase of the C/C preform density. The tribological properties of various C/C-SiC composites showed a stable friction phase at an intermediate braking stage. When the density of C/C preforms was around 1.78 g/cm(3), the C/C-SiC composites exhibited excellent friction coefficients (0.438 and 0.465), and low wear rates (linear and weight wear rates were 0.450 mu m/ time and 0.123 g/cycle, respectively). Furthermore, the C/C-SiC composites fabricated with non-woven carbon fiber needling preforms showed relatively a higher friction value and wear rate than those of C/C-SiC with PANOF integral C/C preforms. Therefore, C/C-SiC composites have been considered promising friction materials for braking system applications.