Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: Nickel-base superalloys having gamma prime strengthening precipitates in a gamma matrix and little or no tertiary incoherent phases, such as delta, delta variants and eta.

Abstract: Nickel-base composite niobium bearing alloys including delta and/or eta strengthening phases in addition to gamma prime precipitates in a gamma matrix.

Abstract: An article may include a substrate, a diffusion barrier layer formed on the substrate, and a protective layer formed on the diffusion barrier coating. The diffusion barrier layer may include iridium.

Abstract: In some examples, an article may include a superalloy substrate and a coating on the superalloy substrate. In accordance with this example, the coating includes a diffusion barrier layer on the substrate and a wear resistant oxide layer over the diffusion barrier layer. The diffusion barrier layer may include iridium and the wear resistant oxide layer may include at least one of silica, zirconia, or chromia.

Abstract: Nickel-base composite niobium bearing alloys including delta and/or eta strengthening phases in addition to gamma prime precipitates in a gamma matrix.

Abstract: In some examples, an article may include a superalloy substrate and a coating on the superalloy substrate. In accordance with this example, the coating includes a diffusion barrier layer on the substrate and a wear resistant oxide layer over the diffusion barrier layer. The diffusion barrier layer may include iridium and the wear resistant oxide layer may include at least one of silica, zirconia, or chromia.

Abstract: Nickel-base superalloys having gamma prime strengthening precipitates in a gamma matrix and little or no tertiary incoherent phases, such as delta, delta variants and eta.

Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: An article may include a substrate that comprises a nickel alloy. The substrate may include a modified subsurface region and a bulk region. The modified subsurface region may include a first composition and the bulk region may include a second composition different than the first composition. The modified subsurface region may include at least one of a reactive element or a noble metal, and the modified subsurface region comprises a thickness of less than about 0.3 ?m measured in a direction substantially normal to a surface of the substrate. The modified subsurface region may be formed by depositing a layer including at least one of the reactive element or the noble metal in a layer on a surface of the substrate and introducing the at least one of the reactive element or the noble metal into the modified subsurface region using ion bombardment.

Abstract: An article may include a substrate, a diffusion barrier layer formed on the substrate, and a protective layer formed on the diffusion barrier coating. The diffusion barrier layer may include iridium.

Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: A nickel base powder metallurgy superalloy gas turbine engine disk for a compressor or turbine. The wrought powder metallurgy gas turbine engine disk has desirable fatigue crack growth resistance and a superior balance of tensile, creep rupture and low cycle fatigue strength characteristics. In one embodiment the disk defines a segregation free homogenous structure.

Abstract: The present invention generally relates to an external cylindrical or conic section shaped fixture which is tightly fit around the same shaped workpiece prior to expansion forming to a final dimension. During expansion forming, the external fixture is also deformed and is therefore designed for one-time use. The external cylindrical or conic section shaped fixture of the present invention is particularly useful for expansion forming of workpieces which contain brazed lap joints. The external fixture restrains, out-of-plane joint rotation and reduces the stress concentrations existing near the lap joints. Additionally, the external fixture provides additional load carrying capability to allow better load distribution during expansion forming. No change is required to the expansion forming machinery or the inner expander dies (jaws) with use of the present invention.

Abstract: An improved method of forming a rotor includes the steps of hot isostatically pressing powdered metal to form disc-shaped hub sections. Each of the hub sections has a rim portion with a relatively large or coarse grain size to optimize high temperature creep properties. The central portion of each hub section has a relatively small or fine grain size to optimize tensile strength and reduce cycle fatigue at intermediate temperatures. Dispersion of any defects in the hub sections is promoted by plastically deforming the hub sections. Preformed blades are placed in an annular array between a pair of the hub sections and the hub sections are bonded together to interconnect the blades and hub sections.