Abstract: An article such as a gas turbine blade or vane has a superalloy substrate, and a coating system deposited on the substrate. The coating system includes a protective layer overlying the substrate, and, optionally, a ceramic thermal barrier coating layer overlying the bond coat. The protective layer has an uppermost layer with a composition including platinum, aluminum, and, in atom percent, from about 0.14 to about 2.8 percent hafnium and from about 2.7 to about 7.0 percent silicon, with the atomic ratio of silicon:hafnium being from about 1.7:1 to about 5.6:1.

Abstract: A process for creating microgrooves within or adjacent to a TBC layer applied to a gas turbine engine component such as a blade or vane. The process includes the steps of applying a bond coat to the surface of the substrate. A wire mesh is placed a predetermined distance above the bond coat surface. With the wire mesh in position, about 0.002 inches of an inner TBC is applied over the bond coat. The wire in the wire mesh causes a shadow effect as the TBC is applied, so that there are variations in the thickness of the applied TBC, forming micro channels. The wire mesh is removed and an additional outer TBC layer is applied over the inner TBC layer, and the variations in thickness are bridged by the continued deposition of the columnar TBC over the inner TBC layer, forming the microgrooves.

Abstract: A nickel-base superalloy article has a surface protective layer comprising nickel, from about 20 to about 35 weight percent aluminum, and from about 0.5 to about 10 weight percent rhenium. The protective layer, which is preferably an overlay coating of the beta (&bgr;) phase NiAl form, is formed by depositing nickel, aluminum, rhenium, and modifying elements onto the substrate surface. A ceramic layer may be deposited overlying the protective layer.

Abstract: A metallic substrate has a substrate surface having a substrate surface of nickel, a substrate aluminum content, and other alloying elements. A maskant is applied overlying the substrate surface to produce a masked substrate surface having an exposed region and a protected region. The maskant includes a plurality of maskant particles, each particle having a maskant particle composition comprising a maskant metal selected from the group of nickel, cobalt, titanium, chromium, iron, and combinations thereof, and a maskant aluminum content. The substrate is aluminided by contacting a source of aluminum to the masked substrate surface, whereby aluminum deposits on the exposed region and does not deposit on the protected region.

Abstract: An article such as a gas turbine blade or vane has a superalloy substrate, and a coating system deposited on the substrate. The coating system includes a protective layer overlying the substrate, and, optionally, a ceramic thermal barrier coating layer overlying the bond coat. The protective layer has an uppermost layer with a composition including platinum, aluminum, and, in atom percent, from about 0.14 to about 2.8 percent hafnium and from about 2.7 to about 7.0 percent silicon, with the atomic ratio of silicon:hafnium being from about 1.7:1 to about 5.6:1.

Abstract: A protected article includes a substrate, such as a nickel-base superalloy, a protective coating comprising aluminum overlying a surface of the substrate, and an iridium-containing oxygen barrier layer overlying the protective coating. A ceramic thermal barrier coating may overlie the protective coating and the oxygen barrier layer.

Abstract: A cooling system for cooling of the flow path surface region of an engine component used in a gas turbine engine and a method for making a system for cooling of the flow path surface region of an engine component used in a gas turbine engine. The method comprises the steps of channeling apertures in a substrate to a diameter of about 0.0005″ to about 0.02″ to allow passage of cooling fluid from a cooling fluid source; applying a bond coat of about 0.0005″ to about 0.005″ in thickness to the substrate such that the bond coat partially fills the channels; applying a porous inner TBC layer of at least about 0.01″ in thickness to the bond coat, such that the TBC fills the channels; applying an intermediate ceramic layer that is more dense than the inner TBC layer on top of the porous TBC; applying an outer TBC layer over the intermediate layer; and, passing cooling fluid from a cooling fluid source through the channel into the porous TBC.

Abstract: A cooling system for cooling of the flow path surface region of an engine component used in a gas turbine engine and a method for making a system for cooling of the flow path surface region of an engine component used in a gas turbine engine. The method comprises the steps of channeling apertures in a substrate to a diameter of about 0.0005″ to about 0.02″ to allow passage of cooling fluid from a cooling fluid source; applying a bond coat of about 0.0005″ to about 0.005″ in thickness to the substrate such that the bond coat partially fills the channels; applying a porous inner TBC layer of at least about 0.01″ in thickness to the bond coat, such that the TBC fills the channels; applying an intermediate ceramic layer that is more dense than the inner TBC layer on top of the porous TBC; applying an outer TBC layer over the intermediate layer; and, passing cooling fluid from a cooling fluid source through the channel into the porous TBC.

Abstract: The present invention provides active convection cooling through micro channels within or adjacent to a bond coat layer applied to the trailing edge of a turbine engine high pressure airfoil. When placed adjacent to or within a porous TBC, the micro channels additionally provide transpiration cooling through the porous TBC. The micro channels communicate directly with at least one cooling circuit contained within the airfoil from which they receive cooling air, thereby providing direct and efficient cooling for the bond coat layer. Because the substrate includes an actively cooled flow path surface region that can reduce the cooling requirement for the substrate, the engine can run at a higher firing temperature without the need for additional cooling air, achieving a better, more efficient engine performance. In one embodiment, a metallic bond coat is added to an airfoil with pressure side bleed film cooling slots.

Abstract: A thermal barrier coating (TBC) and method for forming the coating on a component intended for use in a hostile environment. The coating and method are particularly directed to inhibiting sintering, grain coarsening/growth and pore redistribution in the coating during high temperature excursions by providing limited amounts of extremely fine carbide-based and/or nitride-based precipitates preferably formed at defects and pores at and between the grain boundaries of the TBC microstructure. The precipitates pin the TBC grain boundaries and pores during high temperature excursions, with the effect that the TBC microstructure is thermally stabilized. A coating containing the carbides and/or nitrides can be formed using a physical vapor deposition technique in an atmosphere that contains carbon and/or nitride gases or compounds thereof, or by evaporating a source material that contains carbon, carbon-containing compounds, carbides and/or nitrides.

Abstract: A thermal barrier coating (TBC) for a component intended for use in a hostile environment, such as the superalloy turbine, combustor and augmentor components of a gas turbine engine. The TBC is formed of zirconia that is partially stabilized with yttria (YSZ), preferably not more than 3 weight percent yttria, and to which one or more additional metal oxides are alloyed to increase crystallographic defects and lattice strains in the TBC grains and/or form precipitates of zirconia and/or compound(s) of zirconia and/or yttria and the additional metal oxide(s), the inclusion of which reduces the thermal conductivity of the YSZ to levels lower than conventional 6-8% YSZ. Improvements are particularly contemplated for TBC having a columnar grain structure, such as those deposited by EBPVD and other PVD techniques.

Abstract: A thermal barrier coating (TBC) system and method for improving the thermal fatigue life of a thermal barrier coating. The invention entails modifying the surface morphology of an aluminide bond coat that adheres the thermal barrier coating to a substrate of a superalloy component. The aluminide bond coat has columnar grains, such that grain boundaries are exposed at the surface of the bond coat and define ridges. The surface of the bond coat is then treated so that a sufficient amount of material is removed from the grain boundary ridges and other surface peaks to flatten the bond coat surface, i.e., the ridges and peaks are replaced with flattened surfaces that are nearly parallel to the diffusion zone of the bond coat. By removing these surface irregularities, it is believed that a more stable bond coat surface is created where the critical alumina-bond coat interface will exist following a thermal treatment, such as TBC deposition.

Abstract: An oxidation-resistant coating is described, formed of an alloy containing: about 40 to about 50 atom % aluminum and about 0.5 atom % to about 3 atom % tantalum; with a balance of nickel; cobalt, iron, or combinations thereof. The coating may also include chromium and a precious metal, as well as other components, such as zirconium or molybdenum. A method for applying the oxidation-resistant coating to a substrate is also described. The substrate can be formed of superalloy material, e.g., a turbine engine component. Related articles are also disclosed.

Abstract: At least one airfoil shaped vane made of a low ductility material, for example a ceramic base material such as a ceramic matrix composite or an intermetallic material such as NiAl material, is releasably carried in a turbine vane assembly including inner and outer vane supports by at least one high temperature resistant compliant seal. The seal isolates the vane from at least one of the vane supports and allows independent thermal expansion and contraction of the vane in respect to the support.

Abstract: A cooling system for cooling of the squealer tip surface region of a high pressure turbine blade used in a gas turbine engine and a method for making a system for cooling of the squealer tip surface region of a high pressure turbine blade used in a gas turbine engine. The method comprises the steps of channeling apertures in a tip cap to a diameter of about 0.004″ to about 0.020″ to allow passage of cooling fluid from a cooling fluid source; applying a bond coat of about 0.0005″ to about 0.010″ in thickness to the tip cap such that the bond coat partially fills the channels; applying a porous TBC layer of at least about 0.003″ in thickness to the bond coat, such that the porous TBC fills the channels; applying a dense ceramic TBC layer over the porous layer; and, passing cooling fluid from a cooling fluid source through the channel into the porous TBC. The density of the dense TBC layer can be varied as needed to achieve desired cooling objectives.

Abstract: The present invention provides for cooling the squealer tip region of a high pressure turbine blade used in a gas turbine engine comprising coating the squealer tip with a metallic bond coat. Micro grooves oriented in the radial direction are fabricated into the airfoil on the interior surface of the squealer tip above and substantially perpendicular to the tip cap. A micro groove oriented in the axial direction is fabricated along the joint corner between the squealer tip side wall and the, tip cap to connect and act as a plenum with all of the micro grooves oriented in the radial direction. Tip cap cooling holes are drilled through the tip cap and connected to the micro groove that ultimately forms a plenum. TBC ceramic is then deposited on both blade external surfaces and the tip cavity, forming micro channels from micro grooves as a result of self shadowing.

Abstract: A nickel-base superalloy article has a surface protective layer comprising nickel, from about 20 to about 35 weight percent aluminum, and from about 0.5 to about 10 weight percent rhenium. The protective layer, which is preferably an overlay coating of the beta (&bgr;) phase NiAl form, is formed by depositing nickel, aluminum, rhenium, and modifying elements onto the substrate surface. A ceramic layer may be deposited overlying the protective layer.

Abstract: The present invention provides a process for forming active convection cooling micro channels within or adjacent to a bond coat layer applied to a turbine high pressure turbine airfoil. When placed adjacent or within a porous TBC, the micro channels additionally provide transpiration cooling through the porous TBC. The micro channels communicate directly with at least one cooling circuit contained within the airfoil from which they receive cooling air, thereby providing direct and efficient cooling for the bond coat layer. Because the substrate includes an actively cooled flow path surface region that can reduce the cooling requirement for the substrate, the engine can run at a higher firing temperature without the need for additional cooling air, achieving a better, more efficient engine performance. In one embodiment, a metallic bond coat is applied to an airfoil.

Abstract: The present invention provides active convection cooling through micro channels within or adjacent to a bond coat layer applied to the trailing edge of a turbine engine high pressure airfoil. When placed adjacent to or within a porous TBC, the micro channels additionally provide transpiration cooling through the porous TBC. The micro channels communicate directly with at least one cooling circuit contained within the airfoil from which they receive cooling air, thereby providing direct and efficient cooling for the bond coat layer. Because the substrate includes an actively cooled flow path surface region that can reduce the cooling requirement for the substrate, the engine can run at a higher firing temperature without the need for additional cooling air, achieving a better, more efficient engine performance. In one embodiment, a metallic bond coat is added to an airfoil with pressure side bleed film cooling slots.

Abstract: The present invention provides for cooling the squealer tip region of a high pressure turbine blade used in a gas turbine engine comprising coating the squealer tip with a metallic bond coat. Micro grooves oriented in the radial direction are fabricated into the airfoil on the interior surface of the squealer tip above and substantially perpendicular to the tip cap. A micro groove oriented in the axial direction is fabricated along the joint corner between the squealer tip side wall and the tip cap to connect and act as a plenum with all of the micro grooves oriented in the radial direction. Tip cap cooling holes are drilled through the tip cap and connected to the micro groove that ultimately forms a plenum. TBC ceramic is then deposited on both blade external surfaces and the tip cavity, forming micro channels from micro grooves as a result of self shadowing.