Abstract: In the repair of a metallic article portion, a metal powder and laser beam are applied concurrently, the laser beam being applied in a power density range of 10.sup.4 to 10.sup.6 watts per square centimeter at an interaction time between the laser and the article and powder of 0.005-2 seconds to generate a repair layer.Apparatus for delivering a consistent, continuous flow of powder comprises the combination of an enclosed powder reservoir including means to introduce a gas under pressure, a mechanical means to feed powder into a conduit, a conduit vibrating means, and a fluid-cooled powder delivery nozzle.

Abstract: A gas turbine including at least a compressor, a combustor, and a turbine is constructed to operate at a preferred thermal efficiency in predetermined compressor and turbine flow pressure ratios. A fluid, such as steam, for example produced by waste heat and pressurized as water, and characterized as having a higher specific heat at constant pressure than effluent from the combustor is introduced into such effluent to provide a turbine operating medium of improved potential to transfer energy downstream of the combustor. Such injection provides effective variable geometry to the system. This injection system maintains such pressure flow ratios substantially independent of engine power output.

Abstract: A rolling element bearing member designed for use in a preselected bearing operation, such as a gas turbine engine, which develops a predetermined operating hoop tensile stress in the member includes a hardened layer contiguous with a ductile core having a hardness less than 50 Rockwell C. For example, the hardened layer is a carburized layer of high hardness in the range of 58-66 Rockwell C. The hardened layer has improved resistance to crack initiation and propagation as a result of providing the layer with compressive residual stress in an amount greater than the predetermined operating hoop tensile stress, for example in the range of about 10-60 ksi to a depth up to about 0.06 inch. Such a member is made by providing a member of a metal alloy having the capability of developing such a hardened layer, and then processing the member to develop the layer in the amount of compression.

Abstract: Repair or replacement of a projection such as a labyrinth seal tooth of a metal having relatively poor weldability characteristics is accomplished by removing a portion or possibly all of the seal tooth down to a pedestal and then metallurgically bonding as by fusing to the pedestal a second metal characterized as having good weldability characteristics when diluted with the first metal, and age hardenable with an aging heat treatment with which the first metal also is age hardenable.

Abstract: A gas turbine engine comprising a compression means, combustion means, a first turbine, and a second turbine is provided with improved thermal efficiency and power output through bypassing a portion of the engine operating fluid from a first engine position downstream of at least a portion of the compression means and upstream of a control area of the first turbine and injecting at least a portion of the bypassed flow downstream of the control area of the first turbine. High pressure steam is injected at a position between the engine position initiating the bypass and the engine position injecting the bypass into the fluid stream. The amount of steam injected is substantially equivalent in mass flow to the removed fluid.

Abstract: A method for applying preselected abrasive particles to an article surface includes providing an electrically non-conductive tape and particle member for use in an electrodeposition type system. The tape includes pores large enough to allow passage of electrodeposition current and electrolyte solution but smaller than the size of abrasive particles to be retained on the tape. The tape has a porous adhesive layer of relatively low tack level, the adhesive carrying the abrasive particles through a first or relatively weak bond. A metallic coating is electrodeposited through pores of the tape and adhesive onto the article surface and about the abrasive particles in contact with such surface. This bonds the abrasive particles to the article surface through a second bond between the metallic coating and the abrasive particle which is stronger than the first, relatively weak bond. Thereafter, the tape and particle member is separated at the first bond from the abrasive particles bonded to the article surface.

Abstract: A method for applying preselected abrasive particles to a cleaned first article surface adjacent a second article surface selected to be substantially free of such abrasive particles includes disposing on the first article surface a first electrically non-conductive tape segment including pores large enough to allow passage of electrodeposition current and electrolyte solution but smaller than the size of abrasive particles to be retained on the first tape segment. The first segment has a porous adhesive layer of relatively low tack level, the adhesive carrying the abrasive particles through a first, relatively weak bond. A second electrically non-conductive tape segment substantially impervious to electrolyte solution and electroplating current and having adhesive on a second segment operating surface is disposed on the second article surface in a manner at least sharing an edge portion with the first segment.

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 gas turbine including at least a compressor, a combustor, and a turbine is constructed to operate at a preferred thermal efficiency in predetermined compressor and turbine flow pressure ratios. A fluid, such as steam, for example produced by waste heat and pressurized as water, and characterized as having a higher specific heat at constant pressure than effluent from the combustor is introduced into such effluent to provide a turbine operating medium of improved potential to transfer energy downstream of the combustor. Such injection provides effective variable geometry to the system. This injection system maintains such pressure flow ratios substantially independent of engine power output.

Abstract: An improved method for determining that coating has been removed from an article surface is provided for use in a method of removing a selected coating from an article surface having a composition different from the coating by impacting the coating with abrasive particles. The improved method includes selecting from the light spectrum a color which provides a color contrast between light emitted from the coating and light reflected from the article surface during coating removal in an impact intensity range using the abrasive particles. Provided is the selected color light environment in which the coated article surface is placed and then impacted with abrasive particles in the impact intensity range to create the color contrast and to remove coating from the article surface, the impact would be conducted until the color contrast disappears.

Abstract: A method and apparatus for masking from treatment selected surfaces of a turbine blade. The blade is positioned in an apparatus which includes a holder enclosing the airfoil section of the blade and a distinct spaced apart mask member elastically secured to the holder and having a deformable surface covering a surface of the blade spaced from the airfoil.

Abstract: A powder mixture for use in a method of repairing a superalloy article includes first and second Ni base superalloy powders. The first powder, characterized by superior hot corrosive resistance along with good oxidation resistance and the substantial absence of melting point depressants selected from Si and B greater than normal impurity levels, is included in the range of 30-70 wt % of the mixture. The second powder has a composition substantially within the same composition range as that of the first powder with the inclusion, by wt, of 0.5-5% B and up to 6% Si.

Abstract: An abradable seal member, which can be a component of a rotary seal in juxtaposition with another member, includes a non-metallic abradable material comprising a halogenated hydrocarbon, for example Teflon material. Such a material, which preferably is porous, has a solids content of at least about 40 weight %, a heat of combustion of no more than about 4000 BTU per pound, the halogenated hydrocarbon being at least about 60 weight % halogen.

Abstract: A method and apparatus for applying filler material to a workpiece in conjunction with a heat producing means, to deposit a heating/molten pool region on the workpiece; wherein the filler wire is introduced into the pool region in a reciprocating manner which alternately advances an end of the filler wire into and out of the pool region; and wherein the heat produced by the heat producing means is varied so that peak heating pulses are initiated and maintained when the filler wire contacts the pool region, and so that the heat producing means maintains a lower, background level when the filler wire is withdrawn from the pool region.

Abstract: An improved brazing alloy, particularly suited for use in high temperature gas turbine engines, has a composition range which exhibits X-ray inspection capability, improved stress rupture properties, good ductiity and oxidation resistance up to 1400.degree. F. The brazing alloy consists essentially of, by weight, about 20-80% Pd, 2-13% Cr, 1-4% B, balance being Ni and incidental impurities. The brazing alloy is capable of brazing in the 1800.degree.-2000.degree. F. temperature range and is less costly than Au-bearing brazing alloys currently in use for brazing in this temperature range.

Abstract: A composite fabric preform and article made of both structural and thermoplastic fibrous materials and a method of making such preform and article, the method improving the handling properties of the composite. A plurality of layers of fabric made from structural fibrous material are disposed in a stacked assembly with layers sequentially adjacent each other. At least each of alternate layers of the alternate layers of fabric include within its weave thermoplastic fibrous material intermixed with the structural fibrous material. The layers of fabric, preferably under pressure, are heated at a temperature sufficient to promote bonding action by the thermoplastic fibers at junctures between fibrous materials.

Abstract: A composite fabric preform and article made of both structural and thermoplastic fibrous materials and a method of making such preform and article, the method improving the handling properties of the composite. A plurality of layers of fabric made from structural fibrous material are disposed in a stacked assembly with layers sequentially adjacent each other. At least each of alternate layers of the alternate layers of fabric include within its weave thermoplastic fibrous material intermixed with the structural fibrous material. The layers of fabric, preferably under pressure, are heated at a temperature sufficient to promote bonding action by the thermoplastic fibers at junctures between fibrous materials.

Abstract: A brazing alloy, particularly suited for use in high temperature gas turbine engines has a composition range which exhibits X-ray inspection capability, adequate stress rupture properties, ductility and oxidation resistance. The brazing alloy composition consists essentially of about 25-95% Pd, up to about 5% Si, up to about 3.5% B, balance being Co and incidental impurities, all percentages being by weight. The brazing alloy is capable of brazing in the 1800.degree.-2100.degree. F. temperature range and is less costly than current Au-bearing brazing alloys currently in use for brazing in this temperature range.

Abstract: A powder alloy mixture for use in a method of repairing high temperature superalloy articles includes a first, higher temperature alloy powder in the range of about 35-65 weight percent of the mixture. The first alloy powder is based on at least one element selected from Ni and Co and is characterized as having good strength and environmental resistance along with the substantial absence of melting point depressant elements selected from Si and B in amounts greater than about 1% Si and 0.5% B. The second alloy powder is of a lower melting temperature alloy of Ni--Cr--Si--B--Co and is characterized by the substantial absence of C.

Abstract: The relative position of a plurality of holes through a surface of a member, the holes having been generated by high energy means, such as a laser, which vaporizes material of the member to produce a light flash, is inspected and controlled as the holes are being generated using a light sensing means which is responsive to the light flash and which observes the relative positions of the holes being produced. The light sensing means signals a hole pattern comparison means which compares the actual hole pattern with a preselected hole pattern. Adjustment can then be made to reposition the high energy beam if required to correct undesirable error in the actual hole pattern during generation of the holes.