Ablation resistance evaluation of carbon fiber reinforced SiBCN composites under arc jet wind tunnel testing

Carbon-fiber-reinforced SiBCN (C f /SiBCN composites) have gained significant attention due to their exceptional high temperature stability and outstanding oxidation resistance, which can be applied in Thermal Protection System (TPS). In this study, arc jet wind tunnel testing, which can effectively simulate the actual atmospheric flight environment and the associated fluid-solid surface interactions, is applied to evaluate the ablation behavior C f /SiBCN composites. The heat flux density during testing is 1.2-1.6 MW·m -2 and the heating temperature ranges from 1200 °C to 2000 °C. After ablation, the surface was covered with an intact oxide layer composed of BN(C) and borosilicate glass. The linear and mass recession rates were as low as 0.268 × 10 -3 mm·s −1 and 1.422 × 10 -3 mg·mm −2 ·s −1 at 1900 °C, respectively. A detail study demonstrate that the oxide layer of ablated product consists of α/β-SiC crystallites embedded within turbostratic B-N-C layers. In order to explore the ablation mechanism, the ablation performance of C f /SiC and C f /SiBCN composites at 2000 °C were compared and investigated.