Enhanced ablation resistance of SiBCNTi ceramics by titanium incorporation

SiBCN ceramic exhibits immense potential for application in high-temperature environments due to its exceptional high-temperature stability. However, its ablation resistance is limited by relatively poor oxidation and thermal shock resistance. Here, SiBCNTi ceramics were constructed through mechanical alloying followed by hot pressing, and the effects of metallic titanium or TiN and TiB₂ compounds as titanium sources on the ablation behavior were systematically investigated for the first time. With titanium element incorporation, ultra-high temperature ceramic phases such as TiCN and TiB₂ phases are formed in the sintered SiBCNTi ceramics, which are expected to enhance the oxidation and thermal shock resistance of the SiBCN ceramic. A distinctive structure where TiO₂ crystals embedded in oxide glass is formed in the ablation center of the SiBCNTi ceramic using metallic titanium as the titanium source, which is deemed advantageous for preserving the integrity of the oxide layer and enhancing the ablation resistance of the ceramic. The SiBCNTi ceramic exhibits mass and linear ablation rates of 2.39 mg s−1 and 0.003 mm s−1, respectively, much lower than the pure SiBCN ceramic and its matrix composites, demonstrating the effectiveness of Ti addition in improving ablation resistance of SiBCN-based ceramics.