Morphology, thermal response and anti-ablation performance of 3D-four directional pitch-based carbon/carbon composites

A high density 3D-four directional carbon/carbon composite was fabricated by hot isostatic pressure impregnation carbonisation using coal tar pitches. The thermo-oxidative, thermophysical and ablation properties of the composite were determined. Thermo-oxidative analysis shows that the carbon matrix is oxidised faster than the fibre. The composite shows a quasi-isotropic heat capacity and coefficient of thermal expansion, whereas its thermal conductivity depends on the fibre volume fraction in the test direction. The ablation in plasma is higher and more severe than in oxyacetylene, and the resistance of carbon fibres to ablation depends on their orientation relative to the flow of ablative gasses.

► 4D-c/c composite was fabricated using carbon fibre rods and coal tar pitches.
► Thermal conductivity of the 4D-c/c in-plane is higher than through-the-thickness.
► Heat capacity and CTE in the 4D-c/c composite show quasi-isotropic behaviour.
► Ablation mechanism of the composite in plasma is different than in oxyacetylene.
► The ablation rate in plasma is ∼10 times higher than in oxyacetylene environment.