The first evidence of the high oxidation resistance of the novel ternary tantalum-iridium-boron phase

ABSTRACT An iridium-based intermetallic material was fabricated at 1600 °C from the powdered mixture of tantalum, iridium, boron, and silicon carbide. The ternary phase Ta7Ir6B8 phase was formed with other refractory compounds including TaC, TaIr3, IrSi, and Ta3B4. The ablation resistance was evaluated at 2000 – 2100 °C. The ablation rate was 7·10-5 g/cm2·s and correlates well with the evaporation rate of Ta2O5. The first evidence of the ability of the ternary Ta7Ir6B8 phase to withstand severe environmental conditions was given. The reasons of the improved oxidation resistance are discussed.