Abstract: A metallurgical joint structure between two workpieces to be joined by soldering or brazing includes a stress release layer of a low yield point metal, preferably silver, gold, copper, palladium or platinum. The joint structure also includes a juxtaposed barrier layer to prevent the diffusion of a solder element, such as tin, to the stress release layer. Preferred barrier layers are chromium, titanium-tungsten and tantalum. Preferably, the joint includes one or more stress relief layer and associated barrier layer combinations in the joint structure for improved joint reliability.

Abstract: A magnetic recording medium includes a successively formed uneven underlayer and magnetic layer. In the process of forming the underlayer, grains of an alloy, whose melting point is in the range of approximately 100 degrees centigrade to approximately 350 degrees centigrade, are deposited on a substrate by using either an evaporation or a sputtering method, while maintaining the substrate temperature at a temperature which allows molten spheres of the alloy to be formed. The preferred alloys include Zn, Mg, Al, In, and Sn systems whose melting points fall within the above-mentioned temperature range. The preferred substrate temperatures are not higher than the melting point of the alloy to be deposited plus 50 degrees centigrade, and most preferably, temperatures equal to approximately the melting point of the alloy to be deposited minus 20 degrees centigrade. The result is a magnetic recording medium suitable for practical use which can be fabricated at a low cost.

Abstract: A rotating labyrinth seal especially useful for effecting sealing between two plenums in aircraft gas turbine engines comprising a base and a plurality of radially-directed seal teeth rings extending circumferentially around the outer peripheral surface of the base. Each of the seal teeth rings has a body portion and a tip portion, with the body portion being substantially thicker than the tip portion. Seal teeth rings of the invention exhibit improved resistance to fatigue crack propagation compared to conventional seal teeth rings.

Abstract: The present invention is directed to a heat treatment for nickel-base superalloys used to make single crystal parts and components for gas turbine engines. The heat treatment is conducted in a vacuum or inert atmosphere and includes the steps of solutionizing in a temperature range sufficient to achieve solution of at least 95% of the .gamma.' phase, preferably 2385.degree.-2395.degree. F., for 2 hours; cooling to 2000.degree. F. at 100.degree. F./min minimum, furnace cooling to 1200.degree. F. in 60 min. or less and thereafter cooling to room temperature; heating to 2050.degree..+-.25.degree. F. for 4 hours; furnace cooling to below 1200.degree. F. in 6 min. or less and thereafter to room temperature; and heating to 1650.degree..+-.25.degree. F. for 4 hours and thereafter furnace cooling to room temperature.

Abstract: There is provided by the present invention an alloy which is mechanically and chemically compatible with advanced nickel-base superalloys and nickel-base eutectic superalloys and which possesses excellent resistance to high temperature oxidation. The alloy of the invention is, therefore, particularly useful as a protective environmental coating for the external surfaces of hot-stage aircraft gas turbine engine components, e.g., rotating blades and stationary vanes, made from such advanced superalloys.

Abstract: A mixture of two powdered alloys of the M, Cr, Al type, M being Co and/or Ni, is disclosed, in one form, for use in providing an abradable surface of an article and is characterized by the substantial absence of B. The first alloy has substantially no Si and has a higher melting range than that of the second alloy. The second alloy has substantially no Y and consists essentially of, by weight, 8-12% Si, 1.5-4% Al, 10-30%Cr, with the balance M and incidental impurities. The total mixture composition consists essentially of, by weight, 10-35% Cr, 4-10% Al, from a small but effective amount up to about 0.09% Y, 2-6% Si, with the balance M and incidental impurities.

Abstract: A method for repairing or manufacturing an article, such as a bladed disk, having an integral projection, for example an airfoil, includes first removing a damaged projection to provide a stub, or in new manufacture providing the stub. A collar shaped to register with the stub is provided and bonded to the stub to generate a stub-collar combination. Then a replacement or new projection member is bonded to the stub-collar combination. Finishing then provides the article. Apparatus includes the combination of a metal attachment die and a heating means retained in a recess of the die during bonding.

Abstract: The present invention is directed to single crystal superalloys of eutectic or near-eutectic composition. The high temperature mechanical properties of the superalloys of the invention are improved by precipitation of dispersoids of a phase of the eutectic into the single crystal matrix during thermal treatment subsequent to solidification of the single crystal from the superalloy melt. During solidification, the growth of the dispersed phase is suppressed.

Abstract: A mixture of two powdered alloys of the M, Cr, Al type, M being Co and/or Ni, is disclosed, in one form, for use in providing an abradable surface of an article and is characterized by the substantial absence of B. The first alloy has substantially no Si and has a higher melting range than that of the second alloy. The second alloy has substantially no Y and consists essentially of, by weight, 8-12% Si, 1.5-4% Al, 10-30% Cr, with the balance M and incidiental impurities. The total mixture composition consists essentially of, by weight, 10-35% Cr, 4-10% Al, from a small but effective amount up to about 0.09% Y, 2-6% Si, with the balance M and incidental impurities.

Abstract: An improved mixture of alloy powders is provied for use in treating a preselected article alloy, for example, to repair or join multiple components of the article. The mixture has at least three distinct groups of alloy powders which together define a mixture composition range, with each alloy powder of the groups characterized by a composition and melting range different from the others and from the article alloy. In a preferred form, the mixture composition range comprises, by weight, 15-30% Cr, 1.5-6% W, 0.4-4% Al, 1-11% Ti, 1-6% Ta, up to 1.5% B, up to 0.5% Si, up to 0.2% Zr, up to 3% Mo, up to 0.3% Hf, up to 6% Cb, up to 2% Re, with the balance selected from Co and Ni along with incidental impurities.

Abstract: A method consisting of a high temperature diffusion treatment, preferably preceded by a hot isostatic pressing treatment, by which the deleterious effects of hard alpha defects may be substantially reduced or eliminated from ingots of titanium or titanium alloys without adversely affecting the subsequent structure and properties of ingots processed by the method and the homogenized, substantially hard alpha and inclusion-free ingots produced thereby.

Abstract: A hollow composite airfoil with an integral internal support rib of fluoroelastomer rubber is formed by bracketing the rib between two silicone rubber mandrels to form a core assembly having a desired aerodynamic shape, then building up on opposite sides of the core assembly separate stacks of laminae of a composite material of graphite (or carbon) and glass fibers impregnated with an epoxy resin, with the two stacks overlapping adjacent to the leading and trailing edges of the core assembly. Heat and pressure are then applied to the core assembly with the laminae thereon to bond together the laminae of each stack, then to bond the two stacks together along the overlapping portions thereof and to bond the two stacks to the rib to form a continuous shell around the core assembly. The mandrels are then removed. One open end of the resulting hollow airfoil is plugged and that end is inserted into a recess in a mounting platform with a predetermined clearance space therebetween.

Abstract: A fluid-cooled article, such as a turbomachinery blading member, is provided with a fluid passage by a method of depositing a first material on a work surface of a mandrel by low pressure plasma deposition. A first member thus generated is separated from the mandrel. In one form, an inner surface of the first member is provided with a surface groove. After depositing a sacrificial material in the groove, a cover material is applied to entrap the sacrificial material. Removal of the sacrificial material provides the fluid passage.

Abstract: A device is provided for efficiently directing nonrotating cooling air into a rotating turbine rotor. The device employs a nozzle to accelerate the cooling air in the direction of rotor rotation. A diffuser-deswirler then directs this air, with curved and expanding flow passages, into corresponding holes in the turbine rotor. With these elements, the device directs the cooling air into the rotating rotor section without significant pressure losses and with a lower resultant cooling air temperature.

Abstract: In one embodiment, the inlet gearbox includes a gearbox housing which is removably coupled to a fan module. The gearbox includes a horizontal gear for removably mating with gear teeth on the stub shaft of the compressor module. The gearbox includes vertical gear means coupled to the horizontal gear means for developing a drive output of the gearbox. A single main shaft bearing is fixedly disposed in the gearbox housing. The main shaft bearing supportably receives a rearward extension of the horizontal gear. The stub shaft is inserted into the rearward extension of the horizontal gear. The main shaft bearing provides the sole rotational support for the horizontal gear of the modular inlet gearbox and for the forward end of the stub shaft of the compressor module. The main shaft bearing is disposed in the inlet gearbox housing in a controlled environment prior to assembly of the inlet gearbox into the gas turbine engine.

Abstract: In one embodiment, a fan blade includes an airfoil portion, a platform portion, a shank portion, and a generally axial dovetail portion of a predetermined axial dimension for matingly engaging a generally axial dovetail receiving slot of substantially the same predetermined axial dimension in a fan disk member. Aft cleat means, including a portion having substantially the same cross section as the dovetail portion, is provided and is integral with the dovetail portion and projects generally axially therefrom. The aft cleat means strengthens the dovetail portion. Methods are provided for fabricating such a blade and for strengthening existing blades. Other embodiments are disclosed.

Abstract: Gas turbine engine superalloy airfoils and other components having unique microstructures and novel combinations of physical properties are produced rapidly and economically by the method of the invention which uses the low pressure/high velocity plasma spray-casting process and segmented mandrels.

Abstract: Gas turbine engine superalloy airfoils and other components made by low pressure/high velocity plasma spray-casting have unique microstructures and, consequently, novel combinations of physical properties superior to those of components of the same alloy compositions made by conventional methods.

Abstract: A large number of electrically conductive solid, dense feed-through paths for the high-speed low-loss transfer of electrical signals between integrated circuits of a single silicon-on-sapphire body, or between integrated circuits of several silicon-on-sapphire bodies, are provided by an electroforming method utilizing periodic reverse-current pulsing.

Abstract: Alignment-enhancing electrically conductive feed-through paths are provided for the high-speed low-loss transfer of electrical signals between integrated circuits of a plurality of silicon-on-sapphire bodies arrayed in a stack. The alignment-enhancing feed-throughs are made by a process involving the drilling of holes through the body, double-sided sputtering, electroplating, and the filling of the holes with solder by capillary action. The alignment-enhancing feed-throughs are activated by forming a stack of wafers and remelting the solder whereupon the wafers, and the feed-through paths, are pulled into alignment by surface tension forces.