Microstructure and mechanical property of short fiber reinforced C/C-SiC composites

Abstract

One-staged forming of porous C/C composites as well as volume fraction control of pores were realized, based on thermophysical property analysis and proportioning design of raw materials. Short fiber reinforced C/C-SiC composites with high densification and low content of residual Si were prepared by hot-pressing-infiltration two-step method at low temperature. The structural evolution of C/C-SiC composites was analyzed in detail, the mechanical properties as well as failure behaviors were also investigated. Results show that the porous C/C composites present bipolar distribution in pore size, adding aramid fibers is an effective method to improve the connectivity of network pores, exhibiting a significant regulatory effect. Both SiC network skeleton and pinning structure with strong interface between SiC matrix and carbon fiber bundle can entrust the excellent mechanical properties of C/C-SiC composites with high carbon fiber content. In addition, the fracture toughness of C/C-SiC composites can be improved significantly with the addition of aramid fibers, resulting in the increase of crack propagation path. The isotropic distribution of carbon fiber in plane and the uniform distribution of ceramic phase between layers play a positive role in improving the bearing capacity and friction stability of C/C-SiC composites.

Keywords

• c/c-sic composites
• hot pressing-infiltration two-step method
• microstructure
• mechanical property