Microstructure and ablation behavior of C/C-HfC composites prepared by precursor infiltration and pyrolysis

C/C-HfC composites were prepared by precursor infiltration and pyrolysis using HfC precursor. The microstructure, mechanical properties, and ablation behavior were investigated. The C/C-HfC composites showed good ablation resistance with a surface temperature over 2573 K during ablation. The ablation process was divided into two steps, with the ablation rate dominated by various mechanisms. During ablation, tree-coral-like HfO2 particles formed and functioned as thermal barrier, and the HfCxOy phase acted as oxygen diffusion barrier, protecting the composites from further ablation. (C) 2015 Elsevier Ltd. All rights reserved.