Effects of oxygen partial pressure on the oxidation of ZrB2-SiC-graphite composites at 1800 °c

The oxidation behaviors of ZrB2-SiC-graphite composites are investigated under low partial pressure of oxygen ranging from 100 Pa to 2000 Pa at 1800 °C. The microstructure of the oxidized specimen was analyzed using XRD, XPS, SEM and EDS. A modified volatility diagram is used to justify the development of the oxide layer in this paper. Results indicate that low oxygen partial pressures have a remarkable effect on phase composition of the surface and the microstructures of oxide layer. The higher oxygen partial pressure enhances the oxidation behavior of ZrB2-SiC-graphite composites.