The oxidation behaviors of a ZrB_2-SiC-ZrC ceramic

摘要

The specimen of a ZrB_2-SiC-ZrC ceramic was heated by the electrical resistance heating and the temperature of the specimen increased linearly to f 750 °C within 40s. ZrB_2-SiC-ZrC ceramic was oxidized in air for 30 min and the microstructure of oxide layer was investigated and discussed. The analysis of the SEM observations combined with EDS confirmed that the layered structure consisted of: (1) a SiO_2-rich glass layer; (2) a thin layer of ZrO_2-SiO_2; (3) a layer of ZrO_2 and/or ZrB_2 from which SiC had been depleted; (4) unaffected ZrB_2-SiC-ZrC ceramic. Furthermore, the oxidation kinetics of ZrB_2-SiC-ZrC ceramic was investigated in detail.