Mechanical properties of silicon impregnated C/C composite material at elevated temperature

Fracture tests were conducted for silicon impregnated C/C composite material at elevated temperature. Two kinds of carbon fiber orientations were used; one was (0/90) cross-ply and the other was (+45/-45) cross-ply. The fracture mode of this material is discussed compared with that of the conventional C/C composite material. The roughness of the fracture surface of silicon impregnated C/C composite material is much smaller than that of C/C composite material. The delamination between layers is not so remarkable in the fracture of silicon impregnated C/C composite material while it is predominant on the fracture surface of C/C composite material. The anisotropy of the tensile strength of silicon impregnated C/C composite material is small compared with that of conventional C/C composite material.