Manufacture and Tribological Behavior of C/C-SiC Brake Composites Modified with Fe-Si Alloy

To obtain a stable coefficient of friction (COF) for C/C-SiC composites at high brake speed, simultaneous infiltration of molten Si and Fe alloy into needled C/C materials was developed for fabricating C/C-SiC composites. Consequently, the effect of Fe-Si alloy on the mechanical properties and tribological behavior of C/C-SiC composites was investigated in this work. The results showed that the C/C-SiC composites were composed of C, SiC, FeSi and FeSi2, respectively. Furthermore, the SiC and Fe-Si alloy were mainly distributed in short woven web cloth and among fiber bundles. C/C-SiC composites modified with Fe-Si alloy exhibited lower compressive and flexural strength. Additionally, the brake curve was smoother, while the wear rate was higher. This indicates that introducing Fe-Si alloy into the matrix can impair the mechanical properties, and increase the wear rate, but also improve the friction curve. The typical brake curves were in the shape of a horse saddle.