Influence of matrix modification on microstructure and properties of carbon fiber reinforced silicon carbide composites

Two-dimensional carbon fiber-reinforced C-SiC binary matrix composites (2D C/C-SiC) with PyC/SiC alternative multilayered matrix were fabricated by chemical vapor infiltration to modify the matrix of 2D C/SiC composites. The microstructure and fracture surface of 2D C/C-SiC composites were investigated, and their mechanical properties were compared to those of 2D C/SiC composites. It is shown that the fracture toughness of 2D C/C-SiC composites is greatly higher than that of 2D C/SiC composites, whereas their flexural strength is approximately the same. The efficiency of matrix modification of 2D C/SiC composites is evident. The improved fracture toughness is due to the multi-stage pull-out of fibers.