Microstructure and mechanical behavior of carbon fiber reinforced carbon, silicon carbide, and copper alloy hybrid composite fabricated by Cu-Si alloy melt infiltration

To improve the toughness and strength of C/C-SiC composites, carbon fiber reinforced carbon, silicon carbide, and copper alloy hybrid composite were designed and prepared via Cu-Si alloy melt infiltration at low temperature. The as-prepared composite was mainly composed of C, SiC, Cu 3 Si, and Si phases. Due to the introduction of ductile Cu alloy in the matrix, the composite exhibited good mechanical properties, especially fracture toughness. Cu reacted with Si to produce the Cu 3 Si phase in the composite’s matrix, which reduced the residual silicon in the normal C/C-SiC composite. The bending strength of the as-prepared composite reached about 258.75 MPa and the fracture toughness was up to about 13.55 MPa·m 1/2 . The improved toughness of the as-prepared composite was mainly attributed to the introduction of soft Cu 3 Si phase.