According to reactions xA and xA the

So it can be inferred that ZrC–SiC was partly oxidized into ZrO2–SiO2, and the mass gain caused by the oxidation of ZrC–SiC made up for the mass loss caused by the oxidation of carbon. At higher temperature (893–1073 K), the mass of C/C–ZrC–SiC specimen decreased gradually and the final mass loss was about 2.53%. Reactions (5) and (6) should be the dominant reactions, during which carbon suffered preferred oxidation than ZrC–SiC.