The Isothermal Oxidation of a New Polycrystalline Turbine Disk Ni-Based Superalloy at 800 °C and Its Modification with Pre-oxidation

Abstract Ni-based superalloys with enhanced oxidation resistance at high temperatures are crucial for next-generation gas turbine engines. A new polycrystalline superalloy (C19) that combines improved microstructural stability environmental has been developed. Its determined through measurements of the specific mass change and morphological evolution formed oxides following furnace exposures 800 °C in air up to 1000 hours; results which were benchmarked against Nimonic 105. C19 showed hybrid Type II/Type III behavior as a marginal Al 2 O 3 former performed similarly established 750 °C. The Wagner model transition from internal external oxide formation predicted should form continuous scale higher temperatures. pre-oxidation treatment 1100 1 hour was, therefore, selected shown dramatically improve during subsequent exposure Oxide cross-sectional analysis protective after treatment, whereas 105 retained discontinuous finger-like intrusions beneath Cr overscale.