Abstract: A computer (21) processes the time between ultrasonic echoes received at a transducer (19) indicative of the outer radius and wall thickness of a workpiece (10) by subtracting (69) the weighted average (80-90) wall thickness from the weighted average outer radius to generate an internal radius for a large number of points around a spiral slice of the workpiece. The internal radii and angles are converted (69) to x and y coordinates. The centroid (X, Y) of each slice of data indicating workpiece cavity internal radii is determined (71) as twice the summation of the x coordinates and twice the summation of the y coordinates of all of the datum points of the slice. The least squares fit (73) of the X coordinates of the centroids of all of the slices and the least squares fit (74) of the Y coordinates of the centroids of all of the slices are then used to determine the average axis of the cavity of the workpiece.

Abstract: A computer (21) processes the time between ultrasonic echoes received at a transducer (19) indicative of the outer radius and wall thickness of a workpiece (10) by subtracting (69) the weighted average (80-90) wall thickness from the weighted average outer radius to generate an internal radius for a large number of points around a spiral slice of the workpiece. The internal radii and angles are converted (69) to x and y coordinates. The centroid (X, Y) of each slice of data indicating workpiece cavity internal radii is determined (71) as twice the summation of the x coordinates and twice the summation of the y coordinates of all of the datum points of the slice. The least squares fit (73) of the X coordinates of the centroids of all of the slices and the least squares fit (74) of the Y coordinates of the centroids of all of the slices are then used to determine the average axis of the cavity of the workpiece.

Abstract: Composite materials comprising beta titanium alloy matrices containing high strength, high stiffness filaments are described. The matrix materials are true beta titanium alloys having very limited solid solubility for the filament materials. This low reactivity permits high fabrication temperatures and high use temperatures without formation of deleterious brittle phases. Also described is a method for fabricating such composites.

Abstract: A method for inspecting a repair insert welded into a hole where the weld is not permitted to penetrate the full depth of the hole. An inspection feature, either grooves at the minimum and maximum weld depths or grooves parallel to the insert axis, is formed on the surface of the repair insert. The insert is welded into the hole using electron beam or laser welding. The structure is then non-destructively inspected to determine whether the inspection feature has been consumed at the minimum required weld depth and has not been consumed at the maximum permitted weld depth.

Abstract: A process is described for inertia bonding a hollow shaft made of superalloy materials without causing compressive deformation in the shaft due to the high compressive forces generated in the segmented collet which grips the shaft. A method is also described for minimizing the residual stress in an inertia bonded joint, where the wall thicknesses of the two shaft portions to be bonded are unequal, by independently controlling the gripping forces on the portions so as to provide equal diameter reduction during the bonding process. A method for converting a front loading inertia bonding machine to a rear loading bonding machine is also described.

Abstract: A rheologically controlled glass lubricant for hot metal working comprises a glass powder, a binder, a rheological agent, and a wetting and viscosity modifier. These materials may be dispersed in a carrier. The lubricant is made by mixing the constituent elements, milling the mixture, and stabilizing the milled mixture. The lubricant can be used in a forging operation by coating a metal part with the lubricant, heating the coated part, placing the coated heated part in a forge, and rapidly applying sufficient pressure to deform the coated metal part into a desired shape.

Abstract: A process for strengthening heavy, thick-section forgings of precipitation age hardenable iron base superalloys. The process includes initial recrystallization to achieve a uniform grain size, intermediate temperature warm working at controlled strain rates and for limited amounts of deformation, and precipitation heat treating. The controlled warm working conditions avoid further recrystallization, thus preserving the strain hardening which improves the mechanical properties.

Abstract: The method involves removing wax from a substrate using a non-chlorinated solvent process. The substrate is dipped in a hot wax bath or heated in an oven to remove substantially all of the wax. The substrate is then submerged in either a single or a series of hot mineral oil baths to remove any remaining wax. The oil is then removed by a semi-aqueous or light organic cleaner. The semi-aqueous cleaner is subsequently removed in an alkaline-base cleaner bath. Following the alkaline-base cleaner is a cleansing with a rinsing solution preferably a countercurrent series of rinses. Finally, the substrate is dried.

Abstract: This invention relates to the grinding of titanium alloys and particularly to the grinding of titanium alloys using electroplated synthetic diamond wheels with surface speeds in excess of 2290 surface meters per minute. Other operating parameters are defined which permit the effective grinding of titanium at high rates and which produce desirable residual surface compressive stresses in the surface of the ground article.

Abstract: A workpiece location and support means as described which is free from any tendency to locate the workpiece in a predetermined position. The workpiece is supported and located by a series of hydraulic actuators which in one condition permit the workpiece to move freely but in another hydraulic condition lock the workpiece in one place and do not permit motion thereof. The present invention has particular application as a workpiece support in inertia bonding machines.

Abstract: A beta titanium alloy having exceptional high temperature strength properties in combination with an essential lack of combustibility is described. In its basic form the alloy contains chromium, vanadium and titanium the nominal composition of the basic alloy being defined by three points on the ternary titanium-vanadium-chromium phase diagram: Ti-22V-13Cr, Ti-22V-36Cr, and Ti-40V-13% Cr. The alloys of the invention are comprised of the beta phase under all the temperature conditions, have strengths much in excess of the prior art high strength alloys in combination with excellent creep properties, and are nonburning under conditions encountered in gas turbine engine compressor sections.

Abstract: An energetic compound having the structural formulaO--O--N--Nis disclosed. Routes for synthesizing the compound involving the reaction of oxygen atoms in the [.sup.1 D] electronic state with N.sub.2 O are also disclosed. The energetic compound is particularly useful as an oxidant in chemical propulsion systems.

Abstract: A procedure is described for the repair of gas turbine engine turbine components which involves the repair of cracks and other defects and the replacement of worn or eroded material followed by the laser melting of a thin layer of metal on the surface of the component in those areas requiring reconfiguration to return to the original dimensions. The reconfiguration by laser melting is also useful for new articles which are out of tolerance, and generally for shaping objects from metal sheet or plate.

Abstract: Methods are described for attaching ceramic fibrous bodies to metallic substrates. Metal fibers or metal wires are woven into the ceramic fibrous body which is to be adjacent the substrate and the exposed portion of these fibers or wires is attached by brazing to the substrate.

Abstract: A method is disclosed for controlling the magnitude and location of the weld notch which results from inertia welding of certain materials, such as superalloys. By controlling the size and geometry of the articles being joined a curved weld zone will result and the material expelled from the weld zone which produces the weld notch will be directed in a fashion which moves the weld notch outside of the original diameter of the articles being joined. The resultant welded article consisting of a larger portion and a smaller portion can be machined to the size of the smaller portion without any residual weld notch.

Abstract: A microstructurally toughened ceramic-particle-reinforced metal-matrix composite article is disclosed. The article exhibits a complex microstructure. The article exhibits high tensile strength, high elastic modulus and high impact resistance. A process for making the article is also disclosed. The process includes positioning structural elments within a metallic container to define one or more void spaces within the container, introducing a quantity of metallic particles or of a particulate mixture of metallic particles and ceramic particles into the void spaces, and consolidating the container, structural elements and particles to form the microstructurally toughened composite article.

Abstract: An article exhibiting superior mechical properties and resistance to oxidation corrosion at elevated temperatures as described. The article has particular utility in gas turbine engines and is comprised of a nickel base superalloy consisting essentially of 3-10% Cr, 12.1-16% Co, 1.0-1.9% Mo, 3-10% W, 0-5% Re, 4-7% Al, 0-1.5% Ti, 0-8% Ta, 0.5-3% Hf, 0-2% Cb, 0-1% V, 0.02-0.12% Zr, 0.03-0.2% C, 0.005-0.25% B, 0-0.15% of an oxygen active element such as yttrium, balance essentially nickel. This composition is melted and directionally solidified in columnar grain form to provide useful articles.

Abstract: Adverse interactions during initial interactions between abradable seal components are minimized by applying a coating to the moving seal component. The coating is nonreactive with the abradable material and provides lubricity during initial seal operation.

Abstract: A dimensionally stable structural joint particularly suited for use in space systems. The joint comprises a connector having at least two tubular sleeves, at least two tubular members, and at least two annular clamping means for securing the tubular members inside the connector. The connector comprises at least two elements, manufactured from a fiber reinforced composite, which, when mated, form the connector. The tubular members are manufactured from a material having a coefficient of axial expansion of substantially zero. The annular clamping means are manufactured from a material having substantially the same coefficient of radial expansion as the tubular members. The combination of the connector comprises at least two elements and the annular clamping means with substantially the same coefficient of radial expansion as the tubular members allows the joint to accommodate radial expansion and contraction while maintaining axial dimensional stability.

Abstract: A microstructurally toughened ceramic-particle-reinforced metal-matrix composite article is disclosed. The article includes discrete regions of ceramic-particulate-reinforced metal matrix which enclosed within and separated from each other by a network of unreinforced metal. The article exhibits high tensile strength, high elastic modulus and high impact resistance.