Influence of Nb, Ta and Ti on microstructure and high-temperature strength of precipitation-hardened Pt-base alloys

Abstract Al was replaced partially by Nb, Ta and Ti in precipitation-hardened Pt-base alloys, resulting in elevated compression strengths at high temperatures. The polycrystalline Pt-base alloys containing 5 at.% Nb and Ta, respectively, are stronger than the single-crystal Ni-base superalloy CMSX-4 in [0 0 1] orientation above 1200 °C. By the addition of Nb, Ta and Ti the γ′ solvus temperature is increased.