Abstract: A rotor disk is inspected using an inspection apparatus including an inspection fixture which has a base, and at least one guide extending from the base. Each guide is slidably engagable to one of the rotor slots of the rotor disk and has a guide side shaped to slidably conform to the rotor slot side, and a guide bottom having a guide bottom surface which, in combination with a slot bottom surface, defines an elongated inspection cavity extending parallel to the axis of revolution of the rotor disk. The inspection fixture is mated to the rotor disk such that each guide slides into one of the rotor slots. A sensor apparatus includes a sensor, such as an eddy current sensor, sized to slide into the inspection cavity with a close facing relation thereto, and a sensor drive that moves the sensor parallel to a direction of elongation of the inspection cavity. Inspection is performed by inserting the sensor into the inspection cavity, and sensing the rotor slot bottom using the sensor.

Abstract: An approach to restoring the cross-section of a bent tube to circularity. The tube is placed into a fixture, so that pressurization does not remove the bend. Liquid is placed into the tube, and pressurized. Pressure is increased until the wall of the tube undergoes plastic deformation, and becomes circular.

Abstract: A method for safeguarding regions of an airfoil adjacent to a work area from collateral damage as a result of laser operations. The method utilizes apparatus that includes a sensor assembly. The sensor assembly is fixedly attached to the laser nozzle assembly and moves with the laser nozzle assembly. The laser operations are controlled by a preprogrammed CNC controller. A fixture is used to position the workpiece in relationship to the nozzle on a laser table, the table movable in response to instructions from the controller. A beam stop material is placed over the regions of the airfoil adjacent to the work area to prevent back wall burn or to absorb reflected laser beam energy and to protect the region from other collateral damage such as stray material. The beam stop material is held in place on the workpiece and the workpiece is held in position on the fixture by elastomeric bands.

Abstract: An eddy current inspection probe for inspecting a preselected surface at least partially defining an opening in a component. The probe includes a cast core having an exterior surface sized and shaped for receipt within the opening of the component and an eddy current array positioned over the exterior surface of the core for generating and detecting magnetic fields in the component to inspect the preselected surface of the component.

Abstract: A connector assembly for connecting an ultrasonic transducer to a transducer fixture of an ultrasonic inspection system. The assembly includes a male connector element including a protrusion having a circular cross section and a mount for connecting the male element to at least one of the transducer and the transducer fixture. The assembly also includes a female connector element including a recess sized and shaped for rotatably receiving the male element protrusion to releasably connect the male connector element to the female connector element and a mount for connecting the female element to at least one of the transducer and the transducer fixture. In addition, the assembly includes a fastener mounted on at least one of the male and female connector elements for releasably fastening the male connector element to the female connector element to retain the male element protrusion in the female element recess and to prevent the male element from rotating with respect to the female element.

Abstract: A method for recovering Pt from Pt-bearing coating on a gas turbine engine component. The component is contacted with a chemical stripping agent to dissolve away constituents of the coating and produce a Pt-bearing film of acid oxidation products at the surface of the component. The film is removed from the component to produce a Pt-rich residue containing at least about 10% Pt. The Pt-rich residue is collected and refined to recover Pt therefrom.

Abstract: A gas turbine engine nozzle includes outer and inner bands. Each of the bands includes segments circumferentially adjoining at corresponding splits. The splits of the inner band are circumferentially spaced from the splits of the outer band. A plurality of vanes are fixedly joined to the outer and inner segments which collectively define an accordion loadpath therethrough.

Abstract: Apparatus and method to facilitate vapor phase coating of turbine airfoils. A dovetail receptacle receives the dovetails of a plurality of airfoils. The airfoils are separated by spacers with the airfoil dovetails sealed in a chamber of the receptacle to facilitate vapor phase coating of airfoil flowpath surfaces and platform upper surfaces of several airfoils simultaneously while masking the dovetail sections.

Abstract: A method of inspecting a preselected area of an electrically conductive component to determine whether flaws are present. The method includes the steps of permanently mounting an eddy current element on the component over the preselected area and energizing the element to generate alternating magnetic fields proximate the component. An electrical signal generated by a secondary magnetic field formed proximate the component is detected using the element and the detected electrical signal is compared to a reference signal to determine whether the detected signal is different than the reference signal. Differences indicate the presence of a flaw in the component. Inspection apparatus for performing this method is also disclosed.

Abstract: Calibration of an eddy current inspection system having an eddy current probe and a rotatable turntable is accomplished using a circular calibration standard having a notch of known dimensions formed therein. The calibration standard is mounted on the turntable for rotation therewith. The eddy current probe is positioned adjacent to the calibration standard, and the calibration standard is then rotated so that the probe scans the notch. By providing a rotating scan of the calibration standard, higher scan speeds and more accurate calibrations are achieved.

Abstract: A method of machining an inner surface of a shroud assembly extending generally circumferentially around a central axis of a gas turbine aircraft engine. The method includes determining pre-machined radial clearances during flight between tips of rotor blades in the engine and the inner surface of the shroud assembly at each of a plurality of circumferentially spaced locations around the shroud assembly. The inner surface of the shroud assembly is machined based on the pre-machined radial clearances to provide a generally uniform post-machined radial clearance during flight between the tips of the rotor blades and the inner surface of the shroud assembly at each of the circumferentially spaced locations around the shroud assembly.

Abstract: A fluid stream is discharged along a workpiece surface toward a boss thereof to form a boundary layer atop the surface. A stream of pliant shot is scrubbed across the boss for selectively abrading target material therefrom while the boundary layer protects the surface from abrasion.

Abstract: A method of removing a ceramic coating (18), and particularly zirconia-containing thermal barrier coating (TBC) materials such as yttria-stabilized zirconia (YSZ), that has been either intentionally or unintentionally deposited on the surface of a component (10). The method entails subjecting the ceramic coating (18) to an aqueous solution containing an acid fluoride salt, such as ammonium bifluoride (NH4HF2) or sodium bifluoride (NaHF2), and a corrosion inhibitor. The method is capable of completely removing the ceramic coating (18) without removing or damaging the underlying substrate material, which may include a metallic bond coat (16).

Abstract: A method for repositioning or repairing holes in metal substrates such as metal components used in jet engines and the like. The hole to be repositioned or repaired is enlarged and a recess is formed at each end of the enlarged hole. A deformable metal insert is then inserted within the enlarged hole and then subjected to physical forces so as to cause it to deform and frictionally engage the walls of the recesses and the enlarged hole so that the insert becomes axially fixed therein. A new, repositioned hole can then be formed in the fixed insert that extends completely therethrough.

Abstract: A cooling hole configuration for an air-cooled component, such as a gas turbine engine airfoil. The cooling hole is configured to have cross-sectional variations and a noncircular-shaped diffuser-type opening that significantly improve the cooling film distribution across the external surface of an airfoil, with the result that heat transfer from the surrounding environment to the airfoil is reduced. The cooling hole is configured to have its central axis at an acute angle to the exterior surface of the airfoil, and defines a noncircular-shaped opening at the airfoil surface. The cooling hole generally has a first region adjacent the airfoil surface and a second region interior to the airfoil.

Abstract: An electrical discharge machining (EDM) apparatus includes a single workpiece fixture for holding a workpiece and a plurality of machining heads for machining different features into the workpiece. For example, a first machining head is arranged to machine a first feature into the workpiece, and a second machining head is arranged to machine a second feature into the workpiece. Each machining head is connected to a separate control system so as to operate independently.

Abstract: A calibration standard for calibrating an eddy current inspection probe sized and shaped to inspect a preselected non-planar feature of a manufactured part. The feature extends in a longitudinal direction and in a lateral direction. Further, the feature has an end profile as viewed in the longitudinal direction having a substantially invariant shape and orientation. The calibration standard includes a body having a non-planar surface extending in a longitudinal direction and in a lateral direction. The standard also has an end profile as viewed in the longitudinal direction of the surface substantially identical to the profile of the feature. The surface of the body has an elongate narrow opening extending into the body substantially normal to the surface and traversing the surface of the body at a substantially constant angle with respect to the longitudinal direction of the surface as viewed normal to the surface.

Abstract: A process for manufacturing components of gas turbine engine combustors, including the steps of performing a plurality of forming steps on a workpiece of a designated material to produce a combustor component of desired size and shape without exceeding a forming limit of the designated material, the forming steps being performed without any intermediate heat treatment on the workpiece.

Abstract: The present invention is a method for operating a gas turbine engine airfoil having leading and trailing edges subject to FOD (foreign object damage) damage. The method includes inspecting the airfoil along at least a first one of the edges having at least a first laser shock peened patch along the first one of the edges, ascertaining FOD lengths of foreign object damage (FOD) extending from the first one of the edges into the airfoil within the patch, and allowing the airfoil to remain in service without repair if the FOD lengths are up to a maximum length of about one-half of a width of the laser shock peened patch, as measured from the edge.

Abstract: A method for accurately sizing and forming the cooling holes of an air-cooled gas turbine engine component on which a protective diffusion coating will be deposited. The method generally entails drilling a hole in a surface region of a substrate, and then measuring the thickness of any recast surface region surrounding the hole and created as a result of a portion of the surface region having melted and then resolidified. The thickness of the additive layer of the diffusion coating that will deposit on a corresponding recast surface region of the component is then predicted based on an inverse relationship determined to exist with the thickness of the recast surface region formed during drilling of the cooling hole. An appropriately-oversized hole can then be formed in the component so that, after depositing the diffusion coating on the component, the additive layer grows sufficiently within the hole to yield a cooling hole approximately having the required final diameter.