Ablation and mechanical behavior of a sandwich-structured composite with an inner layer of Cf/SiC between two outer layers of Cf/SiC–ZrB2–ZrC

• A sandwich-structured composite was designed and fabricated.
• It contains an inner layer of Cf/SiC between two outer layers of Cf/SiC–ZrB2–ZrC.
• The composite exhibits good ablation-resistance for ablating one thousand seconds.
• The composite exhibits low strength reductions after ablation.
• The thickness of the ablation-affected area is small.

A sandwich-structured composite, which contains an inner layer of Cf/SiC between two outer layers of Cf/SiC–ZrB2–ZrC, was fabricated by a technique that involved rapid chemical vapor infiltration and precursor infiltration and pyrolysis. In both cyclic and single ablation conditions for one thousand seconds by an oxyacetylene flame, the composites exhibited good ablation-resistant properties and low strength reductions after ablation because of the introduction of a great amount of UHTCs into the outer layers and the small thickness of the ablation-affected area, respectively. The ablation rate and strength reduction in cyclic ablation were lower than those in single ablation.