Abstract: A dovetail assembly for mounting blades with dovetail roots axially into disk dovetail slots around a disk periphery which is subject to a tensile stress field due to centrifugal and thermal growth induced forces generated by the rotor when the rotor is rotating. The dovetail assembly has stress risers each in the form of a transition fillet between a neck or an area of minimum width and a pressure face which is designed to be a contact surface between complementary blade dovetail roots and disk dovetail slots formed between adjacent disk posts. The region around the stress riser has deep compressive residual stresses imparted by laser shock peening and is radially adjacent the stress riser and extends inward from a laser shocked surface of the component along the transition fillet.

Abstract: The invention is a three-dimensional computed tomography method for inspecting and comparing actual geometry to predetermined geometry of an object. The method includes the following steps: A) three-dimensionally scanning the object using computed tomography to produce multiple slices of actual geometrical data of the object; B) processing the multiple slices of actual geometrical data into actual boundary data which defines internal and external boundaries of the object; and C) producing actual point cloud data from the actual boundary data. The method further includes comparing the actual point cloud data to object geometry predetermined data. The comparing may include outputting an image comparing the point cloud data to the predetermined data and the image may represent the geometry of non-conformance between the point cloud data and the predetermined data. The image may be rotated to present the non-conformance from different viewpoints around the feature.

Abstract: A thermal barrier coating system and a method for forming the coating system on an article designed for use in a hostile thermal environment, such as superalloy turbine, combustor and augmentor components of a gas turbine engine. The method is particularly directed to a coating system comprising an APS bond coat on which a thermal-insulating APS ceramic layer is deposited, wherein the oxidation resistance of the bond coat and the spallation resistance of the ceramic layer are increased by diffusing platinum, palladium, hafnium, rhenium and/or rhodium into the bond coat. The diffusion process is performed so as not to alter the surface roughness of the bond coat, which is maintained in a range of about 200 to about 500 .mu.inch Ra.

Abstract: A device exists for translational friction welding of a first component and a second component. The device includes a holder to hold the first component within an open ended frame having an open space within for receiving the first component. The frame includes a base and transversely spaced apart first and second members which longitudinally extend from the base to an open end of the frame at which is located a clamping feature used to clamp the first component in the holder with a clamping force having force components oriented along three orthogonal axis and has opposing tapering pressure surfaces which open outwardly in a first direction and taper inwardly in a second direction which is perpendicular to the first direction. A sacrificial block on the second component has block ends with surfaces that conforms to the surfaces of one of the clamping features. In a preferred embodiment the clamping feature is a compound wedge shaped notch and the block ends have corresponding compound wedge shapes.

Abstract: An electromagnetic peening apparatus includes a first electromagnetic coil having a first face configured to conform to a first surface of a workpiece, and a second electromagnetic coil having a second face configured to conform to a second surface of the workpiece. A carriage positions the first and second coils in abutting contact with the workpiece at respective first and second faces and surfaces. A power supply powers the coils to produce electromagnetic force therein to plastically deform the workpiece at the first and second surfaces to effect a compressive layer therein.

Abstract: A turbine engine including an oil flow path through the low pressure system shaft which, as compared to at least one known oil flow path, facilitates increasing the rated torque and life of the low pressure system shaft is described. In one embodiment, the lubrication opening in the low pressure shaft is oriented so that with respect to a plane along which an outer surface of the low pressure shaft substantially extends, the center axis of the lubrication opening is substantially normal to the plane. As a result of this configuration, the stress concentration in the low pressure shaft at the location of the lubrication opening is substantially reduced. In addition, such a lubrication opening is relatively easy to form as compared to the known, angularly oriented lubrication shaft.

Abstract: A portable three axis scanner is usable to inspect a gas turbine engine spool in situ upon removing a fan module from the engine. The scanner includes a drive assembly mountable to a forward end of the spool, and a support assembly mountable to an aft end of the spool. A support beam extends between the drive and support assemblies, and a carriage assembly is mounted thereon. The carriage assembly includes a probe support for mounting a removable scanner probe for inspecting the inside of the spool by ultrasonic or eddy current inspection. The drive assembly includes means for axially translating the carriage assembly, means for rotating the carriage assembly, and means for radially translating the probe support and probe thereon so that the probe has three-axis movement including axial, circumferential, and radial, respectively, for being selectively positioned inside the spool between the forward and aft ends thereof for inspecting the spool.

Abstract: A tandem tool point apparatus for simultaneously machining surfaces on opposite sides of a thin wall may be used on an annulus having flat machining surfaces or on a circular wall having curved machining surfaces. The tool has spaced apart first and second tool points mounted in first and second tool holders respectively and a coupling element for coupling the first and second tool holders together to maintain the first and second tool points in tandem during a machining operation on the opposite sides of the wall. The apparatus preferably includes a tandem adjusting element for simultaneously adjusting the space between the tool points. A spacer may be used between the holders extending longitudinally over a portion of a length of the holders and the adjusting element longitudinally disposed between the tool points.

Abstract: A method of forming and inspecting beam drilled holes, and in particular laser beam drilled holes, in an article, such as a turbine blade or vane airfoil, with a hollow interior. The method includes (a) filling the hollow interior with a beam blocking material having fluorescent material, (b) beam drilling the holes in the wall through to the hollow interior, and (c) inspecting the hole under an ultraviolet light. The beam blocking material preferably includes a wax material and step (a) includes filling the hollow interior with a melted mixture of the wax and fluorescent materials. The wax material may be a pattern wax material suitable for use in making turbine blade investment casting molds and the fluorescent material may be a fluorescent penetrant.

Abstract: An apparatus for aiming an ultrasonic beam to nondestructively test an object has an ultrasonic transducer for generating the ultrasonic beam having a beam axis and impinging the ultrasonic beam upon the object. The apparatus includes a laser aiming apparatus for directing at least one laser beam having a laser sight line substantially coaxial with the ultrasonic beam axis.The laser aiming apparatus, in one embodiment of the invention, includes a cross-hair apparatus for generating a laser beam cross-hair having a center along the laser sight line. Another embodiment of the present invention provides an ultrasonic mirror apparatus for bending the ultrasonic beam and which has a mirror made of a material that is substantially transparent to the laser beam.

Abstract: A fluid cooled article having a protective coating on a surface, for example an air cooled gas turbine engine article having a Thermal Barrier Coating, includes through an article wall a fluid cooling passage, and typically a plurality of passages, having openings sized to maintain desired fluid flow, unobstructed by coating within the passage at an exit opening. The passage has a first or inlet opening, which establishes the amount of fluid flow through the passage, and a second opening through which the flow exits the passage through a wall surface on which the coating is deposited.

Abstract: An apparatus produces compressive stress in a component surface. Positioning of a contact area of the component surface is controlled to situate a contact area of the component surface relative to an indenter element. The indenter element is fixtured to cause an indentation at the contact area. The force of the indentation is measured as the indenter element contacts the contact area, and controlled responsive to the amount of force measured and the desired compression. The system allows deep compressive stresses to be generated without the surface damage associated with conventional peening.

Abstract: A method of forming a thermal barrier coating on an article designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly directed to increasing spallation resistance of thermal barrier coatings composed of an aluminum-containing bond coat formed on the surface of an article, and an insulating ceramic layer overlaying the bond coat. Processing steps include forming the bond coat on the surface of the article, and then treating the surface of the bond coat with laser energy so as to form a diffusion barrier layer of alumina. Thereafter, a ceramic material is deposited on the surface of the diffusion barrier layer so as to form the insulating ceramic layer. A preferred technique for the treating step is to scan the surface of the bond coat with an ultraviolet laser beam characterized by an appropriate beam geometry and fluence to yield the desired diffusion barrier layer.

Abstract: An on the fly method of laser shock peening a gas turbine engine part by continuously moving a metallic gas turbine engine part while continuously firing a stationary laser beam, which repeatably pulses between relatively constant periods, on a portion of the part with sufficient power to vaporize material on the surface of the portion of the part with the pulses around laser beam spots formed by the laser beam on the surface and form a region having deep compressive residual stresses extending into the part from the laser shock peened surface. Flowing a curtain of water over the surface upon which the laser beam is firing while moving the part until the laser shock peened surface is completely covered by laser beam spots at least once. The surface may covered by a paint which is then the material used to produce the plasma or the surface may be unpainted and the metal of the part is used to produce the plasma.

Abstract: A system is provided for reducing ice mass on an aircraft engine. A compressor inlet temperature and pressure sensor measures total temperature and total pressure at the inlet to the engine compressor. An ice shield is provided, wherein a plurality of wedge portions has multiple protrusions for promoting ice formation in multiple locations. The ice shield is separable from the sensor with which it interfaces. The ice shield comprises straight angle wedge shapes and curved surfaces to separate and minimize ice accretion in desired locations. The mass of each resultant ice formation is reduced to a size that the compressor inlet blades can withstand without deformation.

Abstract: An infrared suppressor system for a gas turbine engine is provided for suppressing infrared radiation associated with the hot metal parts of the engine and with the hot exhaust gases exhausted from the engine. The system features a unique arrangement of multiple baffles that are connected together as a single baffle module. The baffle arrangement permits mixing of hot and cool gas flows while eliminating line-of-sight infrared radiation in an axially compact suppressor. The baffles are additionally linked together into a single insertable baffle module that permits removal of the baffle module when infrared suppression is unnecessary.

Abstract: A lubricating tool includes a longitudinally extending casing, a resilient absorbent medium disposed within the casing, and longitudinally extending slits radially extending from a longitudinally extending centerline essentially in a center of the absorbent medium. A longitudinally extending pilot hole extends along the centerline and the slits radially extend away from the pilot hole. A lubricant supply passage extends from a lubricant supply aperture in the casing through the absorbent medium to the pilot hole and, preferably, the aperture is internally threaded to accept a tube leading to a pressurized supply of lubricant such as grease.

Abstract: A method and apparatus for laser shock peening a portion of a surface on a workpiece with a laser beam directed through a curtain of water confined to the surface by a confining device that confines the water curtain on the surface essentially without any air gaps between the surface and a transparent wall of the confining device. The confining device may also incorporate a back pressure mechanism for producing a back pressure in the curtain of water over the surface such as a nozzle shaped portion of the transparent wall through which the continuous water curtain is introduced by a water nozzle. Automated mechanisms such as robotic arms may be used for positioning the confining wall a predetermined distance away from the surface portion and optionally a water supply nozzle to provide the curtain of water over the surface.

Abstract: A method of laser shock peening a gas turbine engine article by loading the article such that a portion of the article to be laser shock peened is placed in a loaded condition while the portion is laser shock peened using a laser to fire a laser beam with sufficient power to vaporize material on a laser shock peening surface of the portion of the article to form a region in the portion having deep compressive residual stresses imparted by the laser shock peening process extending into the article from the laser shock peened surface. The loaded condition may be either in compression or preferably tension.

Abstract: A laser beam is shaped by eclisping it with a mask of desired shape. The shaped beam is used to drill a hole corresponding to the shape of the beam.