Abstract: An article of manufacture includes a metallic nonfoam region, and a ceramic foam region joined to the metallic region. The ceramic foam region is an open-cell solid ceramic foam made of ceramic cell walls having an intracellular volume therebetween. The ceramic is preferably alumina. The intracellular volume may be empty porosity, or an intracellular metal such as an intracellular nickel-base superalloy.

Abstract: A turbine component such as a turbine blade is clamped into a fixture having a base upon which a remainder of the fixture is supported and a stop which limits the movement of the turbine component. The fixture further has two clamp arms affixed to the base and which controllably clamp against one pair of the pressure surfaces of the root to force the turbine component against the stop, which preferably is contacted by another pair of the pressure surfaces of the root. When the turbine component is clamped in this position, its root may be readily shaped as by grinding.

Abstract: A water-testing apparatus tests an article such as a turbine airfoil component having at least two water flow passage article inlets. The apparatus includes an apparatus body having a water inlet, and an attachment head integral with the apparatus body. The attachment head includes a holder that receives the article therein in sealing contact with an article seal, and at least two ports, each port being in registry with at least one of the at least two water flow passage article inlets. A water flow controller within the apparatus body has a controller inlet in water-flow communication with the water inlet, at least two controller outlets, each controller outlet being in water-flow communication with one of the ports of the attachment head, and a flow-control valve disposed in a water flow path between the controller inlet and the controller outlets. The flow-control valve is controllable to controllably connect a single one of the controller outlets at a time to the controller inlet.

Abstract: An article includes a cylindrical object such as a linear variable differential transformer (LVDT) and a support body having a keyed slot therethrough. The keyed slot has a cylindrical aperture elongated along an aperture axis and a slot extending radially from the cylindrical aperture. A sleeve is received in the keyed slot and includes an annular segment of a hollow cylinder received within the cylindrical aperture and having a first annular end and a second annular end, an inner annular diameter DI sized to slidingly receive the cylindrical object therein, and an outer annular diameter DO sized for the annular segment to fit snugly within the cylindrical aperture. The cylindrical object is received within the annular segment of the hollow cylinder. A first tab extends from the first annular end into the slot, and a second tab extends from the second annular end into the slot and contacts a side of the slot.

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: An internal passage of an article such as a gas turbine airfoil is coated with an aluminum-containing coating. To accomplish this coating process, a coating slurry of a mixture of a carrier component of water and a hectorite clay or a bentonite clay, together with a solids component of a source of aluminum, a halide activator, and an oxide dispersant, is prepared. The coating slurry is applied to the internal passage of the gas turbine airfoil and dried. The gas turbine airfoil and the applied coating slurry are heated to form an aluminum-containing coating bonded to the internal passage of the gas turbine airfoil. Excess coating material is removed from the article internal passage.

Abstract: A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction.

Abstract: A workpiece is electrodischarge machined using a machining apparatus having a workpiece holder, an electrode holder having an electrode mounted thereto, and a power supply providing an electrical voltage and current. The workpiece is mounted in the workpiece holder, and the electrode is positioned adjacent to a machining location of the workpiece. The method further includes furnishing a source of a flow of conditioned water, directing the flow of conditioned water from the source into the machining location of the workpiece, without submerging the machining location in a liquid, and applying a voltage from the power supply such that an electrical current flows between the workpiece and the electrode holder so that metal is removed from the workpiece into the flow of conditioned water.

Abstract: A near-surface defect in a nickel-base superalloy article having a nil-ductility range is weld repaired with a low-power, directional, spatially confined heat source. During the weld repair procedure, the body of the article is maintained at room temperature. Simultaneously, the surface of the article is locally melted in the region of the near-surface defect using the heat source to form a melted region, and thereafter the melted region is allowed to solidify. The heat source produces a shallow weld pool that allows the near-surface defect to be floated to the surface in the case of an inclusion, or welded closed in the case of a surface crack or near-surface void.

Abstract: A hollow composite structure is inspected using an ultrasonic inspection apparatus including a yoke having a base, a first arm extending from the base, and a second arm extending from the base parallel to the first arm. A first ultrasonic transducer is affixed to the first arm, and a second ultrasonic transducer is affixed by a spring mount to the second arm in facing relation to the first ultrasonic transducer. A retractor is affixed to the spring mount to permit the second ultrasonic transducer to be retracted away from the first ultrasonic transducer against a spring bias. The ultrasonic inspection apparatus is positioned by placing one of the arms adjacent to the interior surface, one of the arms adjacent to the exterior surface, and the base extending through the access opening.

Abstract: A method is provided for refurbishing a service operated metallic coating on a substrate alloy, the coating including at least within a coating outer surface at least one oxide chemically grown from at least one coating element, for example Al, and chemically bonded with the coating outer surface as a result of thermal exposure during service operation. Growth of the oxide has depleted at least a portion of the coating element from the coating. The method comprises removing the oxide from the coating outer surface while substantially retaining the metallic coating, thereby exposing in the coating outer surface at least one surface void that had been occupied by the oxide. The retained metallic coating is mechanically worked, substantially without removal of the retained coating, to close the void, providing a treated metallic coating surface over which a refurbishing coating is applied.

Abstract: An undersize repair region of a gas turbine engine stationary shroud is repaired with a sufficient mass of a repair material. The repair material includes a first fraction of a first powder of a first alloy component, and a second fraction of a second powder of a second alloy component. The first alloy component and the second alloy component have different solidus temperatures. The repair material is placed in the repair region. The repair material and the repair region are heated to melt the repair material but not the repair region, and thereafter the repair material and the repair region are cooled to solidify the repair material.

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: An article is formed of a single crystal having a composition, in weight percent, of a modifying element in an amount of from about 0.2 to about 2.0 percent by weight hafnium, from about 0.1 to about 0.5 percent by weight zirconium, or combinations thereof, and a base alloy composition of from about 4 to about 20 percent cobalt, from about 1 to about 10 percent chromium, from about 5 to about 7 percent aluminum, from 0 to about 2 percent molybdenum, from about 3 to about 8 percent tungsten, from about 4 to about 12 percent tantalum, from 0 to about 2 percent titanium, from 0 to about 8 percent rhenium, from 0 to about 6 percent ruthenium, from 0 to about 1 percent niobium, from 0 to about 0.1 percent carbon, from 0 to about 0.01 percent boron, from 0 to about 0.1 percent yttrium, and balance nickel and incidental impurities.

Abstract: A turbine blade is coated by first applying a particle-entrapped tip coating to the tip of the airfoil. An aluminum-containing coating is thereafter applied to the airfoil, including to the tip of the airfoil overlying the particle-entrapped tip coating. The aluminum-containing coating is applied by providing a source of aluminum contacting the airfoil that deposits aluminum onto the airfoil at a coating temperature, and heating the airfoil to the coating temperature so that the aluminum-containing coating is deposited onto the airfoil, and so that the aluminum-containing coating and the particle-entrapped tip coating are diffused into the turbine blade substrate. The step of applying the aluminum-containing coating occurs without substantial prior interdiffusing of the particle-entrapped tip coating with the tip of the airfoil as a separate step.

Abstract: A protective structure includes a substrate made of a nickel-base superalloy component of a gas turbine engine, and a ceramic thermal barrier coating overlying and bonded to the substrate. The ceramic coating is an open-cell solid foam of aluminum oxide ceramic cell walls having a porous interconnected intracellular volume therebetween. The ceramic coating is prepared by depositing a precursor material onto the surface of the substrate. The precursor material includes a sacrificial ceramic, typically silicon dioxide, and a reactive metal, typically aluminum, which is reactive with the sacrificial ceramic to form an open-celled ceramic foam. The sacrificial ceramic and the reactive metal are reacted together to form ceramic cell walls of an oxidized ceramic of the reactive metal, preferably aluminum oxide, and an interconnected intracellular volume therebetween filled with an intracellular metal. The intracellular metal is thereafter removed to leave a porous intracellular volume.

Abstract: A gas turbine component article has an airfoil section and is formed of a nickel-base superalloy. An unmasked region of the airfoil section has a platinum aluminide protective coating, and a masked region of the airfoil section has an aluminide coating. The platinum aluminide preferably is deposited at a trailing edge of the airfoil section that is susceptible to low-cycle fatigue damage when a platinum aluminide coating is present.

Abstract: Abradable coatings for turbine engine shrouds are formed from biscuits formed of silicon-diffused powdered alloy compositions which are processed with an HF precursor to strip oxides from the coating during processing, the alloy blends comprising MCrAl(Y)n alloys in which n is 0, 1 or more.

Abstract: An optical system has an outer dome and a detector system with an optical train and a sensor disposed to receive an optical ray passing sequentially through the outer dome and the optical train. The optical train includes a solid catadioptric imaging lens which is symmetric about a lens axis. The solid catadioptric imaging lens has a bore therethrough coincident with the lens axis, to prevent stray light from reaching the sensor. The bore is desirably filled with an opaque material or has a ground glass wall.

Abstract: A nickel-base superalloy article substrate has more nickel than any other element and a nominal bulk composition of carbon. A protective layer is deposited overlying the surface of the article substrate. The protective layer includes aluminum and one or more of the reactive elements hafnium, zirconium, yttrium, lanthanum, and cerium. The depositing of the protective layer includes steps of decarburizing locations where the carbon may serve as a barrier to the mobility of the reactive elements within the protective layer, and depositing an aluminum-containing protective layer overlying the substrate. The decreasing of the carbon concentration may be accomplished. by decarburizing the substrate, depositing a platinum-containing layer and then decarburizing, depositing an aluminum-containing layer in a reducing atmosphere, and/or decarburizing the deposited protective layer. A ceramic thermal barrier coating may be deposited overlying the protective layer.