Oxidation behavior and phase transition of ZrB2–SiCw–ZrO2f ceramic

• The oxidation behavior and phase transition of ZrB2–SiCw–ZrO2f ceramic have been investigated.
• The flexural strength after oxidized at 800 °C for 30 min is 11% higher than the initial strength.
• It is proved the oxidation product formed at lower temperature is beneficial to crack healing.

The oxidation behavior and phase transition of ZrB2–SiCw–ZrO2f ceramic had been investigated by in situ high-temperature XRD, XPS, SEM, EDS and TEM measurements. The initial oxidation temperature of most ZrB2 was 1000 °C and no significant oxidation of SiC was found up to 1200 °C. The oxidation products formed at lower temperatures would penetrate into the pores and flaws on the surface, which was beneficial to crack healing. In order to improve the oxidation resistance of this system, it should be focused on decreasing the oxygen diffusivity and the volume expansion caused by phase transition.