Significant improvement of the short-term high-temperature oxidation resistance of dense monolithic HfC/SiC ceramic nanocomposites upon incorporation of Ta

The short-term oxidation (i.e., exposure time of up to 20 h) of dense monolithic (Hf,Ta)C/SiC-based ceramic nanocomposites at temperatures from 1200 to 1500 °C is presented and discussed. The oxidation behavior of HfC/SiC is similar to that of other UHTCs, indicating that it is mainly determined by the HfC phase. Ta incorporation into HfC leads to a strong decrease of the parabolic oxidation rates (3–4 orders of magnitude). Unlike HfC/SiC,...