Microstructure and mechanical properties of Cf/SiC–Al composites fabricated by PIP and vacuum pressure infiltration processes

Abstract

In the present study, 3D needle-punched Cf/SiC–Al composites were prepared by precursor infiltration and pyrolysis (PIP) and vacuum pressure infiltration processes. The microstructure and mechanical properties of the as-prepared 3D needle-punched Cf/SiC–Al composites were investigated in comparison to the porous 3D needle-punched Cf/SiC composites and the dense 3D needle-punched Cf/SiC composites with the same carbon fiber fabric. The results showed that the open porosity of 3D needle-punched Cf/SiC–Al composites was 4.63%, while the open porosity of the porous 3D needle-punched Cf/SiC composites and the dense 3D needle-punched Cf/SiC composites was 27.23% and 11.68%, respectively. Furthermore, the compressive strength of 3D needle-punched Cf/SiC–Al composites was significantly improved compared to the porous 3D needle-punched Cf/SiC composites, increasing from 168 ± 17 MPa to 445 ± 15 MPa, which was approached that of the dense 3D needle-punched Cf/SiC composites (451 ± 32 MPa). The microstructural investigations revealed that most of the pores were filled with Al alloy, improving the bearing capacity of the matrix of 3D needle-punched Cf/SiC composites.