D. L. Ballard, S. L. Semiatin, P. L. Martin, Air Force Research Laboratory, Wright-Patterson AFB, OH
Platinum- and iridium-modified gamma-gamma prime superalloys are being evaluated for high-temperature use due to their superior oxidation resistance compared to conventional nickel-base superalloys. These materials also retain excellent strength at temperatures in excess of 1100°C due to their higher gamma prime solvi. Because of their cost and density, however, specific applications must be chosen carefully. One product form of particular interest comprises thin gage sheet and foil for thermal-protection-system applications. Initial research to evaluate the conversion of subscale ingots of PGM alloys to wrought form and subsequent conventional pack rolling to obtain sheet will be reviewed for three experimental alloys.
Summary: Platinum- and iridium-modified γ-γ' superalloys are being evaluated for high-temperature use due to their superior oxidation resistance compared to conventional nickel-base superalloys. These materials also retain excellent strength at temperatures in excess of 1100
oC due to their higher γ' solvi. Because of their cost and density, however, specific applications must be chosen carefully. One product form of particular interest comprises thin gage sheet and foil for thermal-protection-system applications. Initial research to evaluate the conversion of subscale ingots of PGM alloys to wrought form and subsequent conventional pack rolling to obtain sheet will be reviewed for three experimental alloys.
