Preparation, ablation behavior and thermal retardant ability of C/C-HfB 2 -SiC composites

Abstract C/C-HfB2-SiC composites were prepared by precursor infiltration and pyrolysis followed by reactive melt infiltration. Thermogravimetric analysis showed that C/C-HfB2-SiC composites possessed better oxidation resistance than that of C/C composites. Ablation behavior and thermal retardant ability of C/C-HfB2-SiC composites were investigated using oxyacetylene torch. Compared with C/C, thermal retardant ability of C/C-HfB2-SiC composites was improved by 80.45%, which was 406 °C/mm. After ablation for 90 s, the linear and mass ablation rates of C/C-HfB2-SiC composites were reduced by 73.59% and 77.84%, which were 2.06 μm·s− 1 and 0.129 mg·cm− 2·s− 1, respectively. Two typical morphologies of HfO2 skeleton layer and borosilicate glassy layer were formed after ablation, which were indicated to be beneficial for the improvement of thermal retardant ability and ablation performance.