Oxidation resistance of Zr2(Al(Si))4C5-based composites at ultra-high temperature

Oxidation resistance tests were carried out on hot-pressed Zr2(Al(Si))4C5 and Zr2(Al(Si))4C5–20 vol.% SiC using an oxyacetylene torch flame. The temperature of the oxidized specimens exceeded 1860 °C. The mass loss and linear oxidation rates of Zr2(Al(Si))4C5–20SiC for 200 s were 0.29 mg s−1 cm−2 and 0.1 μm s−1, respectively, far lower than those of Zr2(Al(Si))4C5 (0.48 mg s−1 cm−2 and 0.5 μm s−1). The improved oxidation resistance was attributed to the formation of a coherent compact scale, which acts as an effective barrier against the inward diffusion of oxygen.