Abstract: A coating apparatus for coating interior surfaces of internal passages of a workpiece, such as a turbine engine component is provided. The coating apparatus comprises a vessel defining an internal space, a plate dividing the internal space into a first chamber and a second chamber, a divider supporting the plate, and the plate having at least one cut-out for receiving a portion of the workpiece having the internal passages to be coated.

Abstract: A coating apparatus for coating interior surfaces of internal passages of a workpiece, such as a turbine engine component is provided. The coating apparatus comprises a vessel defining an internal space, a plate dividing the internal space into a first chamber and a second chamber, a divider supporting the plate, and the plate having at least one cut-out for receiving a portion of the workpiece having the internal passages to be coated.

Abstract: A method for coating internal surfaces of a turbine engine component comprises flowing an aluminide containing gas into passages in the turbine engine component so as to coat the internal surfaces formed by the passages, allowing the aluminide containing gas to flow through the passages and out openings in external surfaces of the turbine engine component, and flowing a volume of a gas selected from the group consisting of argon, hydrogen, and mixtures thereof over the external surfaces to minimize any build-up of an aluminide coating on the external surfaces.

Abstract: A coating apparatus for coating interior surfaces of internal passages of a workpiece, such as a turbine engine component is provided. The coating apparatus comprises a vessel defining an internal space, a plate dividing the internal space into a first chamber and a second chamber, a divider supporting the plate, and the plate having at least one cut-out for receiving a portion of the workpiece having the internal passages to be coated.

Abstract: Novel materials and methods for repairing/reclassifying superalloy components are described herein. These materials are non-traditional blends of materials having a much higher base material content than traditional repair/reclassification materials. In embodiments used to repair/reclassify nickel-based components, these materials may comprise about 5-18.9 weight percent of a low melting point alloy and about 81.1-95 weight percent of a base material. In embodiments used to repair/reclassify cobalt-based components, these materials may comprise about 15-30 weight percent of a low melting point alloy and about 70-85 weight percent of a base material. These materials can be used to repair surface defects and/or build up worn or eroded areas of a component to meet precise dimensional and metallurgical requirements. These materials create robust repaired components having a dense, isothermally solidified structure having minimal borides and a high re-melt temperature.

Abstract: According to the invention, an article that is exposed to high temperature e.g., over 1000° C. during operation is disclosed. In one embodiment, a method for a gas turbine engine includes a directionally solidifed metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant overlay coating such as an MCrAlY or a noble metal containing aluminide or corrosion inhibiting ceramic is located on portions or the blade not previously covered with such coatings, e.g., the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions. Where the airfoil is also created, the airfoil coating may have a composition different from that of the coating on the underplatform surfaces.

Abstract: A process is disclosed for forming an improved aluminide coating which includes one or more oxygen active elements. A metallic substrate is coated with an overlay coating, such as an MCrAl coating, including one or more oxygen active elements such as yttrium, hafnium and silicon, by a conventional overlay process such as low pressure plasma spray. A metal, preferably a Series VIII transition metal such as platinum, is applied to the substrate, for example by electroplating. The substrate is then aluminized, for example by chemical vapor deposition, and is preferably heat treated. A ceramic thermal barrier may also be applied. The present invention provides an active element containing aluminide coating having a more consistent composition and having improved durability, either as a standalone coating or as a bond coat for a subsequently-applied thermal barrier coating.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g., over 1000 ° C. during operation is disclosed. In one embodiment, a turbine blade for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant noble metal-containing aluminide coating is located on portions of the blade susceptible to corrosion and/or stress corrosion cracking, such as the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g., over 1000° C. during operation is disclosed. In one embodiment, a turbine blade for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant noble metal-containing aluminide coating is located on portions of the blade susceptible to corrosion and/or stress corrosion cracking, such as the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g., over 1000° C. during operation is disclosed. In one embodiment, a turbine blade for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant noble metal-containing aluminide coating is located on portions of the blade susceptible to corrosion and/or stress corrosion cracking, such as the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g., over 1000° C. during operation is disclosed. In one embodiment, a turbine blade for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant overlay coating such as an MCrAlY is located on the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions. Where the airfoil is also coated, the airfoil coating may have a composition different from that of the coating on the underplatform surfaces.

Abstract: A fixture for selectively masking a turbine blade 60 includes a locator 10 with a separable receptacle 40 having portals 50. Guide bars 18 extend from the locator for guiding a pair of shield carriers 20 between deployed and retracted positions. Each shield carrier has a shield 26 projecting therefrom. In use, a turbine blade 60, whose root 70 includes a fir tree attachment 72 and a damper pocket 74, is mounted on the fixture so that the receptacle embraces the blade root. The shield carriers are translated along the guide bars until the shields penetrate through the portals and into the receptacle thus segregating the attachment 72 from the damper pocket 74. Masking powder 84 is then compressed into the receptacle to envelop the attachment while leaving the damper pocket unmasked.

Abstract: A fixture for selectively masking a turbine blade 60 includes a locator 10 with a separable receptacle 40 having portals 50. Guide bars 18 extend from the locator for guiding a pair of shield carriers 20 between deployed and retracted positions. Each shield carrier has a shield 26 projecting therefrom. In use, a turbine blade 60, whose root 70 includes a fir tree attachment 72 and a damper pocket 74, is mounted on the fixture so that the receptacle embraces the blade root. The shield carriers are translated along the guide bars until the shields penetrate through the portals and into the receptacle thus segregating the attachment 72 from the damper pocket 74. Masking powder 84 is then compressed into the receptacle to envelop the attachment while leaving the damper pocket unmasked.

Abstract: A fixture for selectively masking a turbine blade 60 includes a locator 10 with a separable receptacle 40 having portals 50. Guide bars 18 extend from the locator for guiding a pair of shield carriers 20 between deployed and retracted positions. Each shield carrier has a shield 26 projecting therefrom. In use, a turbine blade 60, whose root 70 includes a fir tree attachment 72 and a damper pocket 74, is mounted on the fixture so that the receptacle embraces the blade root. The shield carriers are translated along the guide bars until the shields penetrate through the portals and into the receptacle thus segregating the attachment 72 from the damper pocket 74. Masking powder 84 is then compressed into the receptacle to envelop the attachment while leaving the damper pocket unmasked.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g., over 1000° C. during operation is disclosed. In one embodiment, a method for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant overlay coating such as an MCrAlY or a noble metal containing aluminide or corrosion inhibiting ceramic is located on portions or the blade not previously covered with such coatings, e.g., the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions. Where the airfoil is also coated, the airfoil coating may have a composition different from that of the coating on the underplatform surfaces.

Abstract: According to the invention, an article that is exposed to high temperatures, e.g.. over 1000° C. during operation is disclosed. In one embodiment, a method for a gas turbine engine includes a directionally solidified metallic substrate, e.g., a superalloy, which defines an airfoil, a root and a platform located between the blade and root. The platform has an underside adjacent the root, and a corrosion resistant overlay coating such as an MCrAlY or a noble metal containing aluminide or corrosion inhibiting ceramic is located on portions or the blade not previously covered with such coatings, e.g., the underside of the platform and the neck. The applied coating prevents corrosion and stress corrosion cracking of blade in these regions. Where the airfoil is also coated, the airfoil coating may have a composition different from that of the coating on the underplatform surfaces.

Abstract: The invention includes a low activity localized aluminide coating for a metallic article made by positioning a coating material, preferably in the form of a tape, on a portion of the article. The coating material comprises a binder, a halide activator, an aluminum source, and an inert ceramic material. The coating material and the article are heated in an inert atmosphere between about 1800.degree. F. (982.degree. C.) and about 2050.degree. F. (1121.degree. C.) for between about four and about seven hours thereby producing a low activity localized aluminide coating having an outward diffusion aluminide coating microstructure characterized by two distinct zones, an inner diffusion zone and an outer zone including between about 20-28 percent, by weight, aluminum.

Abstract: The invention includes a low activity localized aluminide coating for a metallic article made by positioning a coating material, preferably in the form of a tape, on a portion of the article. The coating material comprises a binder, a halide activator, an aluminum source, and an inert ceramic material. The coating material and the article are heated in an inert atmosphere between about 1800.degree. F. (982.degree. C.) and about 2050.degree. F. (1121.degree. C.) for between about four and about seven hours thereby producing a low activity localized aluminide coating having an outward diffusion aluminide coating microstructure characterized by two distinct zones, an inner diffusion zone and an outer zone including between about 20-28 percent, by weight, aluminum.

Abstract: The oxidation resistance of MCrAlY-type overlay coatings is improved by incorporating small discrete oxide particles into the coating. The particles are preferably yttrium oxide, and the coating is applied by simultaneously plasma spraying MCrAlY-type powder particles and oxide particles onto a substrate in a nonoxidizing atmosphere. Improvements in resistance to rumpling has also been observed in coatings applied according to this invention.

Abstract: A powder mixture for applying gas phase aluminide coatings to nickel or cobalt base superalloys is described. A preferred mixture consists essentially of Co.sub.2 Al.sub.5, NH.sub.4 F.HF, and chromium metal. The mixture is substantially free of aluminum oxide.