Compressive strength and damage mechanisms of 3D needle-punched Cf/SiC–Al composites

Abstract

3D needle-punched carbon fiber preform was densified by PCS infiltration pyrolysis and Al alloy vacuum pressure infiltration to prepare Cf/SiC–Al composites. The compressive strength of Cf/SiC–Al composites was tested at room temperature. The microstructures of the cross-section and fracture surface were characterized by scanning electron microscopy to clarify the damage mechanism. The Cf/SiC–Al compressive strength was 462 MPa which was almost three times Cf/SiC. The Cf/SiC–Al density was 2.19 g/cm3 which was 1.4 times Cf/SiC. The Cf/SiC–Al open porosity was only 4.60% which was one-fifth of Cf/SiC. The microstructures showed that most of the pores in Cf/SiC were filled with Al alloy. It indicated that the high Cf/SiC–Al compressive strength resulted from the low porosity and high density.