Abstract: A process of producing a ceramic matrix composite gas turbine component and a ceramic matrix composite gas turbine component are provided. The process includes modifying a surface of the ceramic matrix composite gas turbine component to produce a modified surface with a surface roughness of less than 6 micrometers. The modifying is selected from the group of techniques consisting of applying unreinforced matrix plies to the surface, vapor depositing silicon on the surface, honing the surface, applying braze paste to the surface, and combinations thereof. The component includes a modified surface including a surface roughness of less than 6 micrometers. The modified surface being selected from the group consisting of unreinforced matrix plies applied to a surface of the ceramic matrix composite gas turbine component, silicon vapor deposited on the surface, a honed surface, a braze paste applied to the surface, and combinations thereof.

Abstract: Various turbine component preforms are disclosed having near-net shape features. In one embodiment, a turbine casing preform is disclosed. The turbine casing preform includes an as-cast body comprising a partially cylindrical wall section of a turbine casing, the wall section having an inner surface and an outer surface. The turbine casing preform also includes a circumferentially-extending vane slot formed in the wall section on the inner surface. In another embodiment, a turbine nozzle diaphragm preform is disclosed. The turbine nozzle diaphragm preform includes an as-cast body comprising a partially-cylindrical wall section of a turbine nozzle diaphragm having an inner surface and an outer surface. The turbine nozzle diaphragm preform also includes an as-cast, circumferentially-extending seal member projecting from one of the outer surface or inner surface.

Abstract: A method for estimating an operating temperature of component in turbo machinery includes providing body detachably affixed to component, operating machinery, stopping operation of machinery, and removing body. The method includes obtaining concentration profile by determining final concentration of at least one species in first material and in second material, and determining a transient concentration of at least one species between first material and second material. The method includes determining an operating temperature by correlating concentration profile to corresponding operating temperature for system. A system including body is also provided. Body includes at least one species, a first material having a starting first concentration of the species, a second material arranged to permit migration of the species from first material to second material. Species migrates from first material to second material during operation of turbo machinery allowing body to estimate temperature during operation.

Abstract: A method of making a ductile iron article is disclosed. The method includes providing a ductile iron article preform. The method also includes deforming the ductile iron article preform by hot-working to provide a hot-worked portion of the article. The method further includes cooling the article to an austempering temperature. Still further, the method includes austempering the ductile iron article preform for a predetermined time sufficient to provide an austempered article preform comprising an austempered microstructure, wherein the austempered microstructure of the hot-worked portion is different than in other portions of the article. A ductile iron wind turbine shaft is also disclosed. The ductile iron wind turbine shaft has an austempered microstructure comprising an ausferrite matrix and a plurality of graphite nodules. The austempered microstructure has a deformed portion, the deformed portion has a microstructure that is different than the microstructure of the other portion of the shaft.

Abstract: A ceramic matrix composite article and a process of fabricating a ceramic matrix composite are disclosed. The ceramic matrix composite article includes a matrix distribution pattern formed by a manifold and ceramic matrix composite plies laid up on the matrix distribution pattern, includes the manifold, or a combination thereof. The manifold includes one or more matrix distribution channels operably connected to a delivery interface, the delivery interface configured for providing matrix material to one or more of the ceramic matrix composite plies. The process includes providing the manifold, forming the matrix distribution pattern by transporting the matrix material through the manifold, and contacting the ceramic matrix composite plies with the matrix material.

Abstract: An apparatus having reduced wear and friction between CMC-to-metal attachment and interface of the apparatus, including a CMC component having a surface. The CMC component surface is configured for sliding contact with a surface of a metal component, the sliding contact resulting in formation of debris along the contacting surfaces. The surface of the CMC component has an engineered surface feature formed therein to substantially prevent an accumulation of debris along the contacting surfaces.

Abstract: A turbine component, a turbine blade, and a turbine component fabrication process are disclosed. The turbine component includes ceramic matrix composite plies and a feature configured for preventing interlaminar tension of the ceramic matrix composite plies. The feature is selected from the group consisting of ceramic matrix composite tows or precast insert tows extending through at least a portion of the ceramic matrix composite plies, a woven fabric having fiber tows or a precast insert preventing contact between a first set of the ceramic matrix composite plies and a second set of the ceramic matrix composite plies, and combinations thereof. The process includes laying up ceramic matrix composite plies in a preselected arrangement and securing a feature configured for interlaminar tension.

Abstract: A method for modifying a wear characteristic of a rotor blade in a turbine system and a modified rotor blade for a turbine system are disclosed. The method includes implanting ions of one of a Group 6 element, a Group 14 element, or a Group 15 element through an exterior surface of a rotor blade. The rotor blade is one of a compressor blade or a turbine bucket.

Abstract: A method for modifying a wear characteristic of a rotor component in a turbine system and a modified rotor component for a turbine system are disclosed. The method includes implanting ions of one of a Group 6 element, a Group 13 element, or a metalloid element through an exterior surface of a rotor component. The rotor component is one of a rotor wheel or a distance wheel.

Abstract: A method for brazing a component in a power generation system, the brazed power generation system component, and braze are provided to improve repairing power generation systems. The method includes providing the component having a feature in a surface of the component and coating a particulate material with a filler material to obtain a coated particulate material. The method includes preparing the feature to obtain a treatment area and filling the treatment area in the surface of the component with the coated particulate material. The method includes heating the treatment area and surrounding component to a brazing temperature and applying oxidation protection to the treatment area. After the brazing temperature is obtained, the method includes brazing the treatment area and the screen and cooling the component to obtain a brazed joint.

Abstract: Disclosed is a process of fabricating a cast foam product, an intermediate foam product, and a cast foam product. The process includes positioning an expandable component and alloying particles within a die and injecting steam into the die and expanding the expandable component to form an expanded component. The expandable component includes one or more of polystyrene and polymethylmethacrylate. The intermediate foam product includes the alloying particles, the expandable component, and the steam. The cast foam product includes a distribution of the alloying particles and the expanded component, with the alloying particles being physically bound by the expanded component.

Abstract: A method of making an austempered ductile iron article is disclosed. The method includes providing a melt of a ductile iron alloy composition. The method also includes casting the melt into a mold to form a casting. The method further includes cooling the casting to an austempering temperature by circulating a coolant through the mold; wherein cooling comprises solidifying the melt and forming a ductile iron article. Still further, the method includes heating the casting to maintain the austempering temperature for an interval sufficient to form an austempered ductile iron article that comprises a microstructure comprising ausferrite.

Abstract: Casting preforms are provided comprising a casting preform assembly; and a plurality of geometrically shaped bodies, wherein the plurality of geometrically shaped bodies are arranged or interconnected to form the casting preform assembly. Also provided is a method of using a casting preform, comprising forming a casting preform assembly, wherein the casting preform assembly comprises a plurality of geometrically shaped bodies; anchoring the casting preform to an outer surface of a casting mold; introducing a fluid casting material into the casting mold; applying centrifugal force to the casting mold; forming a molded article, wherein at least a portion of the surface of the molded article is reinforced with the plurality of geometrically shaped bodies.

Abstract: A system for heat treating an alloy steel component includes a first enclosure and a second enclosure opposed to the first enclosure. The first and second enclosures define a chamber around only a portion of the alloy steel component. The system further includes a heating element in the chamber to heat the portion of the alloy steel component. A method for heat treating an alloy steel component includes placing a first enclosure against a first side of the alloy steel component and placing a second enclosure against a second side of the alloy steel component. The method further includes creating a substantially airtight chamber around only a portion of the alloy steel component between the first and second enclosures and heating the portion of the alloy steel component inside the substantially airtight chamber.

Abstract: A method of making an austempered ductile iron article is disclosed. The method includes providing a melt of a ductile iron alloy composition. The method also includes casting the melt into a mold to form a casting. The method further includes cooling the casting to an austempering temperature by circulating a coolant through the mold; wherein cooling comprises solidifying the melt and forming a ductile iron article. Still further, the method includes heating the casting to maintain the austempering temperature for an interval sufficient to form an austempered ductile iron article that comprises a microstructure comprising ausferrite.

Abstract: A method for making an equiaxed investment casting. The method utilizes an ultrasonic generator to send an ultrasonic pulse into molten metal in an investment casting mold. The investment casting mold is positioned within a working zone of furnace having low output induction coils for generating a convection current in molten metal. The ultrasonic pulse separates dendrites growing from the face of the mold inward into the molten metal. Instead, equiaxed grains can nucleate within the molten metal. In addition, the ultrasonic pulse and the low output induction coils circulate the molten metal as solute is rejected from solidifying equiaxed grains. The mixing reduces the effects of segregation in the solidifying alloy and assists in nucleating equiaxed grains.

Abstract: A method for estimating an operating temperature of component in turbo machinery includes providing body detachably affixed to component, operating machinery, stopping operation of machinery, and removing body. The method includes obtaining concentration profile by determining final concentration of at least one species in first material and in second material, and determining a transient concentration of at least one species between first material and second material. The method includes determining an operating temperature by correlating concentration profile to corresponding operating temperature for system. A system including body is also provided. Body includes at least one species, a first material having a starting first concentration of the species, a second material arranged to permit migration of the species from first material to second material. Species migrates from first material to second material during operation of turbo machinery allowing body to estimate temperature during operation.

Abstract: A casting system, mold, and method are disclosed for electromagnetically stirring sand castings. In an embodiment, the casting mold includes a mold body having a cavity therein, and a passageway fluidly connecting the cavity with an exterior of the mold body. The passageway allows for introduction of a molten metal into the cavity. The mold body further includes at least one induction coil embedded in a cope of the mold body; and at least one induction coil embedded in a drag of the mold body. The induction coils are configured to generate an electromagnetic field for stirring a molten metal casting while it solidifies inside the mold.

Abstract: A method of making a ductile iron article is disclosed. The method includes providing a ductile iron article preform. The method also includes deforming the ductile iron article preform by hot-working to provide a hot-worked portion of the article. The method further includes cooling the article to an austempering temperature. Still further, the method includes austempering the ductile iron article preform for a predetermined time sufficient to provide an austempered article preform comprising an austempered microstructure, wherein the austempered microstructure of the hot-worked portion is different than in other portions of the article. A ductile iron wind turbine shaft is also disclosed. The ductile iron wind turbine shaft has an austempered microstructure comprising an ausferrite matrix and a plurality of graphite nodules. The austempered microstructure has a deformed portion, the deformed portion has a microstructure that is different than the microstructure of the other portion of the shaft.

Abstract: A method for brazing a component in a power generation system, the brazed power generation system component, and braze are provided to improve repairing power generation systems. The method includes providing the component having a feature in a surface of the component and coating a particulate material with a filler material to obtain a coated particulate material. The method includes preparing the feature to obtain a treatment area and filling the treatment area in the surface of the component with the coated particulate material. The method includes heating the treatment area and surrounding component to a brazing temperature and applying oxidation protection to the treatment area. After the brazing temperature is obtained, the method includes brazing the treatment area and the screen and cooling the component to obtain a brazed joint.