Abstract: The present invention is directed to the achievement of increased gas turbine engine efficiencies through further improvements in nickel-base superalloys used to make parts and components for gas turbine engines. The present invention comprises nickel-base superalloys for producing single crystal articles having a significant increase in temperature capability, based on stress rupture strength and low and high cycle fatigue properties, over single crystal articles made from current production nickel-base superalloys. Further, because of their superior resistance to degradation by cyclic oxidation, and their resistance to hot corrosion, the superalloys of this invention possess a balance in mechanical and environmental properties which is unique and has not heretofore been obtained.

Abstract: A nickel-base superalloy, particularly adapted for use in gas turbine engine single crystal blades and vanes is provided with a specific composition and heat treated in a particular manner to exhibit an improved balance of critical high temperature mechanical properties and resistance to oxidation and hot corrosion significantly superior to presently available alloys. In its broad form, the alloy composition comprises, by weight, 7-12% Cr, 1-5% Mo, 3-5% Ti, 3-5% Al, 5-15% Co, 3-12% W, up to 10% Re, 2-6% Ta, up to 2% Cb, up to 3% V, up to 2% Hf, the balance being essentially nickel and incidental impurities. Nickel-base superalloy single crystal articles formed of the alloy are described, as is the method, including heat treatment, employed to make the article.

Abstract: The present invention is directed to a heat treatment for nickel-base superalloys used to make single crystal parts and components for gas turbine engines. The heat treatment is conducted in a vacuum or inert atmosphere and includes the steps of solutionizing in a temperature range sufficient to achieve solution of at least 95% of the .gamma.' phase, preferably 2385.degree.-2395.degree. F., for 2 hours; cooling to 2000.degree. F. at 100.degree. F./min minimum, furnace cooling to 1200.degree. F. in 60 min. or less and thereafter cooling to room temperature; heating to 2050.degree..+-.25.degree. F. for 4 hours; furnace cooling to below 1200.degree. F. in 6 min. or less and thereafter to room temperature; and heating to 1650.degree..+-.25.degree. F. for 4 hours and thereafter furnace cooling to room temperature.

Abstract: A cast nickel-base alloy article having a complex internal passage and a columnar grain structure is provided with an improved combination of castability and mechanical properties through a control of the amount of gamma prime phase and its related phase formers, a careful control of Co and Al along with Hf and a control of the gamma solution strengtheners, particularly Mo and W.