Abstract: An inertia welding method includes: mounting two workpieces in an inertia welding apparatus; rotating a least one of the workpieces, so as to produce relative rotation of the two workpieces at a predetermined RPM; forcing together the two workpieces with predetermined first weld load so as to cause frictional heating at an interface therebetween; maintaining the first weld load for a first interval; forcing together the two workpieces with a predetermined second weld load greater than the first weld load so as to cause material upset and bonding between the two workpieces, while the rotation brakes to a stop, terminating the weld process; wherein the first and second weld loads are selected so as a produce a specific temperature-distance profile in a selected one of the workpieces, at the termination of the weld process.

Abstract: A gamma prime nickel-base superalloy and components formed therefrom that exhibit improved high-temperature dwell capabilities, including creep and hold time fatigue crack growth behavior. A particular example of a component is a powder metallurgy turbine disk of a gas turbine engine. The gamma-prime nickel-base superalloy contains, by weight: 16.0 to 30.0% cobalt; 9.5 to 12.5% chromium; 4.0 to 6.0% tantalum; 2.0 to 4.0% aluminum; 2.0 to 3.4% titanium; 3.0 to 6.0% tungsten; 1.0 to 4.0% molybdenum; 1.5 to 3.5% niobium; up to 1.0% hafnium; 0.02 to 0.20% carbon; 0.01 to 0.05% boron; 0.02 to 0.10% zirconium; the balance essentially nickel and impurities. The superalloy has a W+Nb?Cr value of at least ?6, is free of observable amounts of sigma and eta phases, and exhibits a time to 0.2% creep at 1300° F. and 100 ksi of at least 1000 hours.

Abstract: Processes for fabricating components to have two or more regions with different grain structures, and components produced by such processes. The processes entail performing at least one forging step on a preform to produce a profile having at least a first portion corresponding to the first region of the component. The preform is formed of a precipitation-strengthened alloy having a solvus temperature, and the at least one forging step comprises a nonfinal forging step performed at a first strain rate and at a first subsolvus temperature that is below the solvus temperature of the alloy. A subsequent forging step is performed on the profile to produce a final profile comprising the first portion and a second portion corresponding to the second region of the component.

Abstract: A gamma prime nickel-base superalloy and components formed therefrom that exhibit improved high-temperature dwell capabilities, including creep and hold time fatigue crack growth behavior. A particular example of a component is a powder metallurgy turbine disk of a gas turbine engine. The gamma-prime nickel-base superalloy contains, by weight: 16.0 to 30.0% cobalt; 9.5 to 12.5% chromium; 4.0 to 6.0% tantalum; 2.0 to 4.0% aluminum; 2.0 to 3.4% titanium; 3.0 to 6.0% tungsten; 1.0 to 4.0% molybdenum; 1.5 to 3.5% niobium; up to 1.0% hafnium; 0.02 to 0.20% carbon; 0.01 to 0.05% boron; 0.02 to 0.10% zirconium; the balance essentially nickel and impurities. The superalloy has a W+Nb?Cr value of at least ?6, is free of observable amounts of sigma and eta phases, and exhibits a time to 0.2% creep at 1300° F. and 100 ksi of at least 1000 hours.

Abstract: Processes for fabricating components to have two or more regions with different grain structures, and components produced by such processes. The processes entail performing at least one forging step on a preform to produce a profile having at least a first portion corresponding to the first region of the component. The preform is formed of a precipitation-strengthened alloy having a solvus temperature, and the at least one forging step comprises a nonfinal forging step performed at a first strain rate and at a first subsolvus temperature that is below the solvus temperature of the alloy. A subsequent forging step is performed on the profile to produce a final profile comprising the first portion and a second portion corresponding to the second region of the component.

Abstract: A forging preform for a turbine rotor disk is disclosed. The preform includes a body of a superalloy material having a mass of about 5000 lbs or more, the superalloy material having a substantially homogeneous grain morphology and an ASTM average grain size of 10 or smaller. 5. A turbine rotor disk is also disclosed. The disk includes a substantially cylindrical disk of a superalloy material having a mass of about 5000 lbs or more, the superalloy material having a substantially homogeneous grain morphology and an ASTM average grain size of about 10 or smaller. A method of making a turbine rotor disk is also disclosed. The method includes providing a superalloy powder material and pressing the superalloy powder material to form a forging preform for a turbine rotor disk.