Abstract: Method of manufacturing broad band attenuation panel structure and the resulting structure therefrom for utilization in high temperature applications, having a maximum temperature in the range of 1600.degree. F. The panel comprises a cellular core constructed of Inconel, titanium alloys, 321 stainless steel, P H hardened stainless steel and the like, positioned between and brazed, liquid interface diffusion (LID) bonded, or diffusion bonded to two facing sheets, one imperforate and one perforated, the facing sheets constructed of a similar material. A sheet of porous metal overlay made of Inconel, nickel, monel, stainless steel alloys or the like is diffusion bonded to the outer surface of the perforated facing sheet.The sequential steps of sizing, cleaning, plating, and heating are set forth as well as the details of pressure, temperature, and protective atmosphere, and protective materials.

Abstract: A continuous strip of brazing foil is partially folded about transverse parallel fold lines in a repetitive pattern. When this strip is positioned between the nodes of honeycomb cells the fold lines will index the cells into proper alignment for assembly. The brazing strip also serves its normal function of providing brazing material for attaching the assembly to other components.

Abstract: An improved honeycomb seal is provided for turbine engines. The subject honeycomb structure comprises a plurality of identical rings. Each ring has a plurality of radially extending convolutions defining alternating ridges and valleys. The rings are fixedly arranged in abutting relationship to define a tubular honeycomb structure having an array of radially extending honeycomb cells. The resultant honeycomb structure is adaptable to both large and small diameter turbine engines. Furthermore, the individual cells of the honeycomb structure can be constructed to any width or depth.

Abstract: A method of brazing the nodes of honeycomb core material and the top and bottom panels to the honeycomb core material to form a sandwich structure. The method comprises the insertion in selected cells of the core, a coil or loop formed of normally flat resilient braze foil ribbon under tension and then releasing the tension to allow the braze foil, coil or loop to be urged against the cell walls under its own resiliency. The top and bottom panels are then installed over the core adjacent to the cell faying edges to form top and bottom surfaces. Pressure is then applied from the panels toward the honeycomb core material. The temperature of the sandwich structure is then elevated until the braze foil is caused to melt. Capillary attraction causes the now liquid braze material to flow into the interstices between the cell nodes and between the faying edges of the honeycomb core cells and the adjacent panels.

Abstract: A corrugated core strip for use in the formation of honeycomb core panels is formed by a punch forming operation which simultaneously forms flanges at the edges of the core strip. The punching operation causes the flanges to be gathered at the troughs of the corrugations. The gathering is accommodated by forming grooves in the flanges which extend toward the flange on the opposite edge of the strip. The use of thicker core strip materials is facilitated, and the configuration both simplifies the manufacture of honeycomb core panels and improves the characteristics of the panels.

Abstract: Method of manufacturing structures from sheets of material having superplasticity as well as diffusion bonding capabilities wherein a combination of diffusion bonding and superplastic forming is performed concurrently with the use of low pressures and a simple heat furnace. The material to be formed and bonded is placed between and sealed in tooling constructed of materials having different degrees of thermal expansion. A low pressure from an external source is applied between the sheets of material to be formed during heating. Forming shims positioned within the tooling provide areas of diffusion bonding when the applied pressure and differential of tooling expansion force the sheets of material together at the shim locations.

Abstract: When conventional honeycomb structures are formed into cylinders, the inner wall made up of the inner edges of the individual honeycombs is circumferentially compressed and the outer wall made up of the outer edges of the honeycombs is circumferentially stretched. As a result, the height of the inner wall increases and the height of the outer wall decreases resulting in a bowing in of the central portion of the cylinder so that the cylinder assumes an hourglass shape. This bowing in can be avoided by corrugating the original ribbon core material in the manufacture of the honeycomb in such a manner that one longitudinal edge of the corrugated ribbon follows a wave form of an amplitude greater than the wave form defining the opposite longitudinal edge.

Abstract: Lightweight capped honeycomb stiffeners 18 for use in fabricating metal or metal/matrix exterior structural panels 14 on aerospace type vehicles 10 and the process for fabricating same are disclosed. The stiffener stringers are formed in sheets (FIG. 6), cut to the desired width and length and brazed in spaced relationship to a skin 16 (FIG. 2) with the honeycomb material serving directly as the required lightweight stiffeners and not requiring separate metal encasement for the exposed honeycomb cells.

Abstract: Two ferrous-based components are bonded together to form a bonded structure and simultaneously a layer is diffused into the surfaces of the components. The process involves first placing the components in juxtaposition, and contacting the juxtaposed components with a molten lead bath having at least one diffusing element therein. One component may be a corrugated sheet and the other may be an uncorrugated or less corrugated sheet, the sheets being in the form of helixes interposed in each other to create a substantial number of fold lines being in contact with the surface of the uncorrugated sheet. Alternately, a sheet with projections may be used in place of the corrugated sheet.

Abstract: According to the invention, there is provided a method for manufacturing a fluid contacting device according to which a single side wall of vertically continuous hollow prism-shaped elements is formed of a single sheet of metal or like material and a plurality of such sheets are regularly arranged and joined together to form the fluid contacting device. By this arrangement, assembling of the fluid contacting device is made very simple, waste of material in forming the side wall sheet can be held to the minimum and an unused portion between a column and the fluid contacting device can be eliminated whereby a fluid contacting efficiency can be improved.

Abstract: Rather than spray coat face sheets of honeycomb panels with powder braze alloy or using foil strips of braze alloy between honeycomb core and face sheets, individual ribbon segments of brazing foil are positioned between successive honeycomb cell vertices or nodes. The arrangement is such that several such ribbon segments will lie essentially in parallel planes to each other and normal to the planes of the top and bottom panel sheets when these panel sheets are positioned to sandwich the honeycomb cells therebetween. Heat can then be applied to melt the ribbon segments resulting in a flow of the brazing material into the nodes as well as the contact line joints made between the top and bottom of the cell walls with the top and bottom panel sheets. Excess brazing material on the panel surfaces covering the open cell portions free of joints is thereby virtually eliminated and desirable ductility and elongation characteristics of the resulting structure are retained.

Abstract: The manufacturing of multi-layer bi-metallic thermo-barrier material utilizing combined brazing and difussion bonding methods of joining together the components of the barrier material.

Abstract: The invention overcomes the difficulty of applying a layer of material e.g. braze material, to a concave surface, by rotating the workpiece having the concave surface, about the axis of revolution of the concavity and the material is applied thereto in powder form and held by centrifugal force. Before stopping rotation, a liquid binder is applied to the material and allowed to set, so as to make the resulting mixture self supporting.

Abstract: The invention comprises a method for manufacturing a load-bearing structural element, and a housing for such manufacture. The method includes positioning outer shell assemblies in the housing to form a hollow space, and positioning honeycomb plates and a central support assembly within the outer shells. The outer shell assemblies are thereafter forced toward each other whereby the edges of the plates are firmly pressed against the adjacent surfaces of the assemblies. The plates and shell assemblies are rigidly interconnected by welding, with the atmospheric conditions in the hollow space being controlled as desired. The housing includes means to initially space the components in the housing prior to pressing and welding.

Abstract: An improved lightweight composite article comprises a base portion and a spaced apart cap portion between which is secured a body portion comprising a plurality of thin metallic ribbons secured between the base portion and cap portion. The ribbons are disposed in substantially unbonded, aligned relationship at an upper wall portion which is integral with the cap portion formed from top edge extensions of the ribbons. The cap portion is disposed angularly to the body portion to provide one boundary of interstices defined within the member. Such a lightweight, porous-type member can be provided with a relatively smooth, substantially continuous surface through the rubbing or smearing of portions of the member surface with a smooth, relatively hard moving rubbing surface such as the peripheral smooth rim surface of a rotating wheel.

Abstract: A composite titanium or titanium alloy structure is made by diffusion bonding upper and lower face sheet components onto opposite sides of a honeycomb core component at an elevated temperature within a furnace under a high vacuum. The components are supported in the furnace upon a slip sheet carried by a glass pad which is, in turn, supported by a lower platen. The weight of an upper platen is transmitted through a slip sheet to the upper face sheet component. The upper face sheet component includes an internal passageway which is coupled to an inert gas supply to expand the passageway by superplastic forming. The upper wall surface of the passageway is restrained by the upper platen so that only the lower wall surface of the passageway is displaced and received in underlying recesses in the honeycomb core component. After expansion, the displaced wall surface is diffusion bonded to the honeycomb core component.

Abstract: A method for fabrication of honeycomb metallic structures combining superplastic forming and metallurgical bonding wherein a face sheet is formed and bonded to another face sheet and a core to form the desired structure. A metal honeycomb core is positioned between the first and second metal face sheets. The first face sheet, which has superplastic characteristics, is brought to within a temperature range suitable for superplastic forming. A pressure loading is applied to the first face sheet causing it to deform against the core and second metal face sheet. The face sheets and core are maintained under coordinated temperature-pressure-time duration conditions to produce metallurgical bonding to one another to form the desired honeycomb structure.

Abstract: Method and apparatus for forming a braze joint along the intersection of grid straps of a nuclear fuel assembly. A substantially cylindrical mold having a cavity therein for holding a braze material and having notches near its bottom end complementary to the grid straps is placed on the grid such that the centerline of the mold is substantially colinear with the intersection of the grid straps. Upon heating the grid and mold assembly, the braze material that has been placed in the mold cavity flows by gravity along the intersection of the grid straps which upon cooling forms a brazed joint.

Abstract: A contoured work top is provided as a new or replacement work surface to fit over an existing support structure such as a desk or table. The work top has a flat sheet of structural material with a top surface and a bottom surface. A second sheet of structural material is provided having a plurality of spaced apart, parallel raised ribs extending across the second sheet which is rigidly connected to the lower surface at tips of the raised ribs thus supporting the second sheet a spaced apart distance from the flat sheet. Also included is at least one flat strip of structural material extending across the second sheet perpendicular to the raised ribs and rigidly connected to the second sheet at locations between the raised ribs. The work top may also have side walls extending downwards from the edges of the flat sheet beyond the second sheet adapted to retain the work top in place on a supporting structure.

Abstract: A method of high temperature assembly of similar or different metallic, nonmetallic or partially metallic components without any direct contact with a cleaning flux, by means of an added metal or alloy with a melting point below that of the most fusible component, characterized in that the components to be assembled and the added metal or alloy are brought to a temperature at least equal to that required to melt the added metal or alloy, in a chamber from which air is substantially evacuated and which contains one or more halogens in the free or combined state, at least a fraction of these free or combined halogens being or passing into the gaseous state for at least part of the heating time.

Abstract: A collimated hole structure formed by constricting a plurality of tubular elements each provided with a core for supporting the tubular element during the constricting operation. The bundle of elements is constricted to a point where the elements effectively fuse into a substantially monolithic body. The cores are then removed, leaving a plurality of extremely small diameter, generally parallel passages in a solid body. The tubular elements may be arranged in any desired array, and thus the passages may be provided similarly in any desired array. The passages may have high aspect ratios and may be closely juxtaposed. In one illustrative application, the collimated hole structure is provided with dielectric film and utilized as an anode portion of an electrolytic capacitor. In another illustrative application, the collimated hole structure is utilized as a tip for a drilling device.

Abstract: A liquid interface diffusion process is provided where a thin deposit (from 1/2 to 4 mils) of nickel (and/or cobalt) having 4-12 weight percent boron is plated on the nickel or cobalt based alloy faying surfaces. In the case of honeycomb sandwich, the plating is applied to the edge of the core or on the facing sheets and the assembly held together in intimate contact and exposed to a temperature sufficient to cause the Ni-B eutectic to melt. At the eutectic temperature a liquid is formed which makes a metallurgical joint. Upon further time at temperature the boron is diffused into the substrate so that isothermal solidification occurs and the boron is diluted to a small concentration. Sufficient time is allowed (on the order of one or more hours) so that the melting point at the joint area is essentially the same as the substrate and the joint is comparable to a diffusion bond.

Abstract: A process and apparatus are provided for assembling a heat exchanger comprising a stack of metallic elements, more particularly a heat exchanger of the cross-flow type.

Abstract: A diffusion and brazing method of bonding honeycomb core material to its facing sheets wherein the core and facing sheets have a predetermined configuration and either the facing sheets or the core edges have had deposited thereon a laminate formed of diffusion bridge or braze alloy material. First, the faying surfaces of the facing sheets and the core are positioned together with the core located between the facing sheets to form the assembly. Secondly, a male plug is inserted into the interior of the assembly wherein the dimensions of the male plug are slightly smaller than the interior dimensions of the asembly and wherein the male plug is formed from a metal having a thermal coefficient of expansion greater than that of the material of the facing sheets and core.

Abstract: A method of making a composite diffusion bonded structure, comprising a honeycomb panel portion made up of a honeycomb core sandwiched between two face sheets, and a load carrying structural member bonded thereto. The honeycomb core, face sheets and structural member are preassembled in a vacuum furnace so as to permit exposure of the surfaces which are to be diffusion bonded. A vacuum is drawn and the assembly is heated to near diffusion bonding temperature with the bonding surfaces still exposed to the vacuum environment. Thereafter, the bonding surfaces are brought into contact with very moderate pressure, and are maintained at a temperature and pressure sufficient for diffusion bonding. The assembly is then cooled, with the result being a substantially unitary diffusion bonded structure.

Abstract: A liquid interface diffusion process for bonding titanium or titanium alloys wherein at least one of the titanium type materials to be fayed is sequentially plated with a total weight of from between 1 and 5 gms/ft.sup.2 of honeycomb core of layers of copper and nickel or an alloy made therefrom. The faying surfaces are then held together to maintain position on alignment, placed in a protective atmosphere, the temperature of the materials are then raised at a controlled rate causing sufficient solid state diffusion to occur and a liquid to form continuing to increase the temperature to a predetermined level and holding at this temperature until a solidification occurs and sufficient additional solid state diffusion occurs producing a desirable dilution of bridge material and titanium at the joint, and then reducing the temperature at a controlled rate to a lower temperature to complete the bonding cycle.

Abstract: In a fabricating process of a metallic honeycomb structure, a plurality of bar soldering materials are laid on a plurality of metallic structure members previously assembled as a honeycomb structure and melted in a heating kiln to complete the soldering joint.

Abstract: The present invention is a lightweight, internally stiffened aerodynamic shell structure with local fittings and a method for fabricating the same. Two typical type structures are the blades and vanes of a turbo fan engine. The invented structure exhibits heretofore unattainable strength and stiffness to weight ratios and a high degree of structural integrity. It is, therefore, particularly advantageous in applications such as the rotating blades in airborne or ground power conversion equipment. It is an aerodynamically shaped structure comprising metallic stiffening material interposed between, and joined to, a pair of relatively thin corresponding metallic face sheets which form the shell skin of the structure. As a function of design requirements, a root fitting, shroud fitting, and tip rib or fitting are solid-state diffusion bonded to the shell structure.