Novel wrought γ/γ′ cobalt base superalloys with high strength and improved oxidation resistance

New polycrystalline Co-base superalloys with γ/γ′ microstructure have been developed, which show excellent mechanical properties and enhanced oxidation behavior. The γ′ solvus temperature of these alloys is comparatively low giving a large processing window. The yield strength of these alloys is similar to that of wrought Ni-base superalloys. However, the creep strength at 750 °C is largely exceeding that of the Ni-base superalloys Waspaloy and Udimet 720Li. Oxidation tests indicate that the oxidation resistance is comparable to commercial Ni-base superalloys.

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