Impact behavior of different cross-ply laminated carbon fiber-reinforced silicon carbide composites under the low velocity

Carbon fiber-reinforced silicon carbide composites (C/SiC) were fabricated by a chemical vapor infiltration process using various ply orientations of 2D carbon fabric in the preform. The effect of ply angles (0°/90°, 45°/-45°, and 0°/45°/90°/-45°) on the low-velocity impact damage of the C/SiC composites was investigated externally and internally. Different depths of pits were formed in the impacted side with fibers sheared off, whereas fiber bundles breakage and matrix cracking appeared on the back side. The sample with 0°/90° ply angles experienced a serious fiber fracture and stratification damage, while the other two samples only showed a slight stratification. The samples with 0°/45°/90°/-45° and 0°/90° ply angles had nearly the same strength loss rate, which was smaller than that of the sample with 45°/-45° ply angle. In 45°/-45°, the ply angle had a major influence on the residual strength as the fibers were at 45° to the loading direction. Comparison of compression strength of the samples before and after impact test showed that the quasi-isotropic laminate improved the impact damage resistance due to the prevention of the devastating crack extension.