Comprehensive oxidation mechanisms of heterogeneous laminated HfB₂–SiC/Ti ceramics under oxyacetylene conditions

A laminated HfB₂–SiC/Ti ceramic prepared via tape casting and spark plasma sintering was characterized upon an oxyacetylene torch test at 2040 ℃. The volatility diagram for the binary HfB₂–SiC system was established along with the detailed ablation microstructure of the upper surface to investigate the ablation behavior of the samples. In addition, the mass (8.93 mg/s) and linear ablation rate (1.22 µm/s) of the laminate are ascribed to the strong oxidation protection of the Ti interlayer by the dense SiO₂ coating on the side surface, retarding the occurrence of oxidation weight loss and exfoliation at the interface. The corresponding oxidation behavior is proposed.