Long-term oxidation behavior of ZrB₂-SiC-B₄C ceramics: Oxidation kinetics and mechanism at 1650 °C

ZrB₂-SiC-B₄C ceramics were fabricated via reactive melt infiltration (RMI), and their long-term oxidation behavior at 1650 °C was systematically investigated. The oxidation followed a parabolic law, indicative of a diffusion-controlled process. After an initially high oxidation rate, the weight gain stabilized at 0.066 mg/(cm²·h) and the oxide layer growth rate reached 0.202 μm/h during the 50–100 h stage. ZrSiO₄ was formed in situ in the SiO₂ layer, effectively pinning the SiO₂ oxide layer and inhibiting further oxygen diffusion. The synergistic formation of borosilicate glass further enhanced oxidation resistance. These findings highlight the excellent high-temperature stability and long-term oxidation resistance of ZrB₂-SiC-B₄C ceramics, making them promising for extreme environment applications.