Extended Investigation of a New Circular Weave for C/C-SiC Applications

Abstract

A new weave has been investigated for applicability in DLR’s liquid silicon infiltration process. It is a circular braid with uni-axial core resulting in a C/C-SiC rod that has subsequently been investigated for tensile, bending and torsion failure and tensile fatigue. The process has worked well resulting in the expected view of the cross-section of the C/C-SiC. However, internal delaminations were observed caused by the matrix shrink between the single braid layers and the uni-axial core especially in CFRP and C/C state. The gap was nearly closed after silicon infiltration. The resulting material has a density of ~1900 kg/m³±2,6% and the residual porosity of ~3% is comparable to standard C/C-SiC (XS). The low scattering of these data proves good reproducibility of the process.