The influence of the precursors on densification and properties of C/C composites

The influence of different precursors on the densification rate, microstructures and flexural strength of C/C composites, 2-D needle punctured felt infiltrated by novel-ICVI, was investigated. The density of the resultant C/C composites was tested by volume method. The density distribution and the correlation between the density and the infiltration time were studied. The flexural strength was determined by three-point blending tests, and the microstructures of resultant materials and the morphology of fracture surface were observed by polarized light microscopy and scanning electron microscopy respectively. The result show that the densification rate of C/C composites using methane as precursors is lower than that using propylene as precursors before 100 h infiltration, while after 100 h infiltration the trend is reversed. The density of C/C composites tends to distribute uniformly, the flexural strength is 250.87 MPa, the flexural modular is 29.29 GPa, and the texture belongs to rough laminar when methane is used as precursor. The density of C/C composites distributes unevenly, the flexural strength is 102.75 MPa, the flexural modular is 11.42 GPa, and the texture belongs to smooth laminar when propylene is used as precursor. Therefore, the methane is an ideal precursor for novel-ICVI Process.