Abstract
• Hot-pressed HfB 2 -HfC/SiBCN ceramics were first successfully fabricated. • The mass and linear ablation rates of the HfB 2 -HfC/SiBCN were 0.0025 mg/s and 0.0004 mm/s. • The ablation mechanisms of HfB 2 -HfC/SiBCN ceramics have been proposed. To further improve the ablation resistance of SiBCN ceramics, nanosized HfB 2 was introduced by mechanical alloying and subsequent reactive hot-pressing techniques to fabricate HfB 2 -HfC/SiBCN multiphase ceramics. The mass and linear ablation rates of the 30 vol% HfB 2 -HfC containing SiBCN ceramics under an oxyacetylene flame for 10 s were lower than those of ZrB 2 -ZrN/SiBCN and SiBCN, reaching to 0.0025 mg/s and 0.0004 mm/s respectively. Even ablated for 60 s, no trace of cracks appeared on the ablation surface. Oxidation of ceramic matrix, denudation of oxides, erosion by the combustion flow and the re-oxidation of the exposed matrix governed the ablation process.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call