Abstract: A wet chemical process for removing an abrasive oxide coating from the surface of a rotating turbine engine component, such as a tooth that forms a rotating air seal with a complementary sealing member. The process generally entails subjecting the coating to a caustic solution at an elevated pressure. The caustic solution is preferably a mixture of water and a base, such as sodium or potassium hydroxide, with the addition of an organic compound being a preferred constituent in a sufficient amount as a solvent media for the caustic solution. A suitable caustic solution contains the base and water at a ratio of about one to one (1:1). If present, the organic compound may constitute about one to about ninety-eight weight percent of the solution. The process is preferably carried out in an autoclave charged with the caustic solution.

Abstract: Tool extension and stability in milling machines is enhanced by providing a spindle extension having a housing attached to the mill head and an arbor rotatively mounted in a bore formed in the housing. The arbor, which is significantly longer than conventional arbors, is supported by first and second bearing assemblies and includes a substantially cylindrical body portion with an integral shank formed on one end thereof for connecting the arbor to a machine tool spindle. A cutting tool is attached to the other end of the arbor.

Abstract: A method for quality assurance of a laser shock peening process uses interferometry to form a fringe image from first and second interferograms of unstressed and stressed laser shock peened patches respectively of a workpiece. The fringe image may then be compared to a predetermined correlation of fringe images for indicating quality assurance. Stressing the laser shock peened patch may include loading the production and test workpieces during the production of the first and second images by interferometry while the production and test workpieces are fixtured. The loading may be done by heating, twisting, or bending of at least a portion of the production and test workpieces. The comparing of the production images of fringes may include comparing fringe characteristics of the laser shock peened patches on the production workpieces laser against fringe characteristics of the predetermined correlation.

Abstract: A nickel-base superalloy article which is susceptible to strain-age cracking and has a directionally oriented, single crystal, or equiaxed grain structure is repaired with minimal welding heat input into the article. The article is first heated to a welding temperature of from about 1650.degree. F. to about 2000.degree. F. in an inert atmosphere. A damaged area of the article is weld repaired using a plasma-transferred arc welder which vaporizes a filler metal in a plasma arc and deposited the vaporized metal onto the article to form a weld overlay. Minimal additional heat is added to the article during welding, as the weldment metal is vaporized remotely from the article.

Abstract: A blank is milled using a rotating mill. A groove having a bottom is first cut across the blank to partially expose a sidewall in the blank. The sidewall is then cut by the mill. By alternately repeating cutting of the groove and sidewall, the groove is milled deeper in the blank to form a pocket along which the sidewall extends. Since the sidewall is formed in steps, improved efficiency and accuracy is obtained therefor.

Abstract: A method for quality assurance of a laser shock peening process of workpieces includes measuring and recording or temporal light intensity data over a short period during the duration of a plasma associated with the vaporized material from laser shots fired during a production laser shock peening process. The recorded temporal data is then analyzed to obtain an instantaneous optical spectrum of the plasma and then used to provide statistical control of the production laser shock peening process. One correlation function of the present invention is based on a time integrated spectral peak intensity wavelength curve for each of the laser firings and for which a peak intensity wavelength is determined for a plurality of times during each plasma of a plurality or all of the firings. Production results from the analysis of the instantaneous optical spectrum is used to determine whether the production laser shock peening process is acceptable.

Abstract: A bib having an improved pocket. The pocket is formed by a pocket panel disposed adjacent a body panel. A longitudinally extending crease is disposed in at least one of the pocket panel and the body panel. In one embodiment, the bib includes an apron panel for facilitating gravitational opening of the pocket. The apron can comprise a longitudinally extending crease. The creases in each panel can extend generally parallel to a longitudinal centerline of the bib.

Abstract: A method for preparing a Ni base superalloy inner wall surface of a body open end, such as an end of a turbomachinery blade, and an end plate, such as a blade tip cap, for brazing together at a rim of the end plate includes electrochemically removing oxides from the inner wall surface. The end plate is prepared, at least at its rim, by first removing surface and subsurface oxides, for example by mechanical abrading or a combination of such abrading and acid cleaning. Then at least the rim is electroplated with Ni which is heated to diffuse the Ni into the rim substrate. This provides an improved combination of surfaces for brazing, for example with a Ni base brazing alloy. After brazing the rim to the inner wall, there is provided an article with an improved relatively low oxide brazed joint, including less than about 20 volume % oxides, and a plate rim of substantially Ni along with elements diffused from the brazing alloy and the rim.

Abstract: A heating apparatus and method for welding a superalloy article. In a preferred embodiment, the apparatus and method entail welding a superalloy article within an enclosure equipped with a thermal radiation-generating device that preheats the article to a temperature of at least 1500.degree. F. prior to welding. The invention more particularly provides a thermally-reflective coating on a reflector member positioned adjacent the thermal radiation-generating device for the purpose of reflecting thermal radiation emitted by the device into the enclosure. The device is then operated to heat the superalloy article to a suitable temperature, e.g., 1500.degree. F. or more, after which a welding operation is performed on the superalloy article.

Abstract: A thermal barrier coating (TBC) system, comprising a metallic bond coat on an article surface and an outer ceramic TBC is repaired by renewing without removing the bond coat. The outer ceramic TBC is removed to expose a bond coat substrate. At least one discrete local surface area of the article surface subject to bond coat degradation is selected from a thermal pattern unique to the article surface from service operation. At least one renewal metal selected from Pt, Rh, and Pd is applied at least to the selected discrete local surface area and heated to diffuse the renewal metal into the bond coat substrate. An environmental resistant coating selected from aluminides and alloys including aluminum is applied at least to the discrete local surface area over the renewal metal. Thereafter, an outer ceramic TBC is applied to the article surface.

Abstract: A method of computed tomographic inspection which uses a Euclidian reference ply model having a corresponding Non-Euclidian ply model which includes reference model plies to extract intensity data from Euclidian slice data (typically having a pixel format) derived from multiple slice X-ray scans using an X-ray scanning system such as the CT system. The multiple slice data is analyzed to determine intensity values for points corresponding to a subject ply of a corresponding reference model ply. The reference model may be a predetermined model such as a mathematically described CAD model file or based on such a CAD model. A preferred method of the present invention includes a transformation of the CAD model data to register the CAD model data to multiple slice data of a standardized object to generate the reference model. Intensity values preferably gray scale pixel values are assigned to points on the reference ply model from the slice data and displayed as a Non-Euclidian image on a monitor.

Abstract: A high temperature vapor coating container, including a hollow interior, resists distortion and cracking at a vapor coating temperature of at least about 1700.degree. F. as a result of making the container of a nonmetallic material having a coefficient of thermal expansion of less than about 4.5.times.10.sup.-6 at the vapor coating temperature, the material being nonreactive with the coating vapor at the vapor coating temperature.

Abstract: A process is provided for producing high temperature composite components from a thermosetting polyimide resin system, and more particularly to an in-mold technique for impregnating a reinforcement fiber preform with the polyimide resin system, and thereafter imidizing the polyimide resin system in such a way that exposure to the uncured (nonimidized) polyimide resin system is minimized. The process entails an injection technique that ensures complete impregnation and wetting of the reinforcing fabric, and complete removal of the condensation byproducts formed during imidization. The imidized component is then cured by heating the component to a temperature sufficient to remelt the polyimide resin system, and then applying pressure and additional heat to cause the polyimide resin system to cross-link to produce the desired composite component. The process results in a fiber-reinforced polyimide matrix component characterized by a void content of less than about three percent.

Abstract: The present invention provides an apparatus for applying discrete particles of absorbent material to a predetermined location on a fibrous web. The apparatus comprises a continuously rotating mask, and a means for directing a supply stream of absorbent particles to form an acute included angle with a diverting surface on the rotating mask. The mask diverting surface splits the supply stream of absorbent particles into a first intermittent stream passing through the mask and a second intermittent stream deflected by the diverting surface. The absorbent particles in one of the first and second intermittent streams is directed to the fibrous web.

Abstract: An apparatus and method for welding a superalloy article. The apparatus generally entails an enclosure adapted for containing a superalloy article, a polarity-reversing plasma transferred arc welder apparatus for welding a localized region of the article, an induction coil for heating the localized region, and elements for sensing and controlling the temperature of the localized region. The induction coil is placed in close proximity to the localized region of the article so that the temperature of the localized region is largely determined and quickly altered by the output of the coil. The polarity-reversing plasma transferred arc welding apparatus is operated at very low currents of not more than forty-five amps, so that the welding apparatus has only a secondary heating affect compared to the induction coil.

Abstract: A method and apparatus for repairing a turbine engine vane segment of at least one airfoil disposed between band or platform members originally assembled in a designed relationship uses locating features integral with at least the band members and used in original assembly. For repair, the members are separated and at least one member is selected for reassembly, while preserving substantially in original form locating features of the selected member. A replacement member is provided for reassembly with the selected member, and the members are reassembled using the preserved locating features for positioning the members in the designed relationship. The apparatus provides elements for moving the segment members into and holding in the designed relationship.

Abstract: A method of laser shock peening a hard metallic article by firing a laser beam on different points of a laser shock peened surface of at least a portion of the article using a laser beam with sufficient power to vaporize material on the surface around laser beam spots formed by the laser beam at the points on the surface, flowing a curtain of water over the surface upon which the laser beam is firing, and firing the laser beam so as to form a plurality of volumetrically spaced apart laser shock peened protrusions extending into the article from the spots such that the protrusions have deep compressive residual stresses imparted by laser the laser beam. The surface may first be coated with an ablative material which the laser beam vaporizes and the method may be an on the fly method of laser shock peening which further includes continuously moving the article while continuously firing a stationary laser beam which repeatably pulses between relatively constant periods.

Abstract: A disposable absorbent article having an expandable component is disclosed. The expandable component can be inflatable, and comprises a gas evolving material and an activating material separated from the gas evolving material by a breakable barrier. The barrier is broken to combine the materials and inflate the component at the point of use of the disposable absorbent article. The inflatable component can comprise a spacer for maintaining a fecal void space in a disposable absorbent article.

Abstract: A method of non-destructively evaluating or validating a processed area of an object such as a metallic laser shock peened surface by determining Rayleigh wave angles at various positions on the surface.

Abstract: A smooth, high density tissue. The tissue has a relatively low caliper, as well as high smoothness and high density. The tissue is calendered from a multidensity, through air dried web.