Structure and properties of C/C-SiC prepared by reactive melt infiltration

C/C materials were prepared by liquid-vaporized and thermal-gradient CVI, and C/C-SiC composite with a density of 2.13-2.28 g/cm³ was prepared by reactive melt infiltration (RMI) in this paper. The microstructure of C/C-SiC was examined using XRD and OM, and its mechanical properties (flexural strength, compressive strength, hardness and fracture ductility), friction and wear characteristics were investigated. The results show that C/C-SiC is composed of C, SiC and Si. The lower the density of C/C, the higher the density of corresponding C/C-SiC. By graphitization, the flexural strength of C/C-SiC decreased from 203-275 MPa to 150-210 MPa and the compressive strength decreased from 463-607 MPa to 403-536 MPa, but the fracture ductility increased from 6.6-8.5 MPa·m^1/2 to 7.3-9.2 MPa·m^1/2. During the sliding friction of C/C-SiC disc to SiC pin, the friction coefficient was about 0.19. By graphitization, the friction coefficient decreased to 0.14-0.15, but the average volume loss rate increased from 3.4 × 10^-3-5.0 × 10^-3 mm³/h to 7.9 × 10^-3-9.8 × 10^-3 mm³/h.