Abstract: A repair coating for superalloy articles, such as gas turbine engine components, includes a volatile organic carrier or water-based carrier, a fluxing agent, a thickening agent, balance a filler mix. The filler mix consists of at least two distinct particulate components. The mix includes a first particulate component having a composition which approximates that of the article being repaired. The mix also includes a second particulate component having a composition approximating that of the article and a melting point depressant, such as boron. This melting point depressant is substantially in excess of that in the article and sufficient to provide melting of a portion of the mix at a processing temperature below the melting temperature of the article. The above filler mix is blended with the other constituents to form the repair coating which is applied to an article.

Abstract: The present invention relates to a tool for accurately controlling the location, volume and containment of an abrasive grit material during a plating operation wherein the grit material and a matrix metal are deposited onto a tip portion of at least one workpiece. The tool of the present invention has an inner component with slots for receiving the workpieces to be coated. The tool also has an outer components having a plurality of through slots for permitting a plating solution to flow therethrough and into a space defined by the inner and outer components. The tool further has a slot defined by portions of the inner and outer component for introducing the abrasive grit material into the space. A screen is provided over the slots in the outer component. The screen helps maintain the abrasive grit material within the space while permitting plating solution to flow into the space. The tool of the present invention further has a trough for collecting unused grit material.

Abstract: The present invention is a clamp with a mechanically attached grommet. The clamp secures and mounts cable, wiring, tubing, or the like to a structure. The clamp uses an outer shell, or a clamp shell, which houses a split grommet to grip the object being clamped. The grommet is mechanically attached to a low stress area in the clamp shell.

Abstract: Blade attachment slots for gas turbine engines are prepared by grinding to a stepped, generally straight sided configuration, semi-finish grinding to an envelope about 0.005 inches to 0.010 inches above the blueprint configuration, and finishing by broaching. This reduces the overall cost of the manufacturing process, permits a more economical use of existing broach machines, and allows greater versatility for short model runs and "just-in-time" production.

Abstract: A thermal mechanical processing sequence for application to alpha-two type titanium is discussed. A typical alloy composition is 14% aluminum, 23% niobium, 2% vanadium, and balance titanium. Tensile ductilities in excess of 10% and up to about 40% are provided in this material by a processing sequence which includes multiple working steps below the beta transus with intervening thermal anneals also at temperatures below the beta transus. Typical rolling start temperatures would be on the order 954.degree. C. (1750.degree. F.). Typical annealing temperatures range from 732.degree. C. (1350.degree. F.) to 954.degree. C. (1750.degree. F.).

Abstract: Unwanted recrystallization during heat treatment of a directionally solidified nickel alloy single crystal casting is prevented by chemical milling the part before heat treatment. Removal of a layer of as little as 0.013-0.050 mm thick, less than two percent of the part thickness, has been found effective.

Abstract: Powder metallurgy techniques are disclosed for fabricating gamma titanium alloy articles (TiAl type alloys) from mixture of powder wherein one species is based on Al.sub.3 Ti and the other Ti.sub.3 Al. Mixtures of these powders in the proper ratio can be compacted, worked, and heat treated to form the desired gamma TiAl alloy.

Abstract: A hafnium nitride coating is applied over the cubic boron nitride layer of conventional CBN tools by the process of arc physical-vapor-deposition at temperatures below the tempering temperature of the core metal. The hafnium nitride coating protects the cubic boron nitride or diamond abrasive and the core, resulting in a grinding tool with greater strength and longer life.

Abstract: A method is taught for the preparation of ceramic fibers by electrophoretic deposition of metal oxide upon a conductive fiber core, which core may be subsequently removed.

Abstract: An aqueous slurry process for producing a diffusion aluminide protective coating in superalloy articles, particularly on internal passages in superalloy articles.Aqueous slurry containing a source of aluminum in particulate form, an inert ceramic particulate, a halide activator compound in particulate form and a viscous aqueous base dispersant is injected into the internal passage or otherwise coated on the internal surface to be protected. The coated article is heated to dry the slurry and remove the aqueous solvent base. The dried, coated article is diffusion heat treated between about 1,350.degree. F. and 2,250.degree. F. for a period of time between approximately 4 hours and 24 hours to transfer the aluminum to the surfaces of the passages and diffuse the aluminum into the substrate material to form the protective coating.

Abstract: Superalloy articles are made more oxidation resistant by a process which includes heat treating the article in the presence of foreign chemical species, at a temperature at which the foreign chemical species reacts with and modifies any oxide film present on the article surface. The heat treatment is best carried out at a temperature above the gamma prime solvus temperature of the article and below the incipient melting temperature of the article. Alternatively, the heat treatment may be carried out within the range defined by the incipient melting temperature of the article and about 150.degree. C. below the incipient melting temperature of the article. At such temperatures the foreign chemical species reacts with and modifies the oxide film on the article surface. Sulfur is then able to diffuse through such modified film, and a more oxidation resistant component is produced.

Abstract: Superalloy articles are made more oxidation resistant by a process which includes heating the article in an environment having a reduced pressure of inert gas and a low partial pressure of oxygen to a temperature at which the sulfur in the article diffuses out. The heat treatment is best carried out at a temperature within the range defined by the incipient melting temperature of the article and about 150.degree. C. below the incipient melting temperature of the article. Alternatively, the heat treatment may be carried out at a temperature above the gamma prime solvus temperature of the article and below the incipient melting temperature of the article. At such temperatures, sulfur readily diffuses out of the article, and a more oxidation resistant component is produced.

Abstract: A yttria strengthened ceria material is disclosed. The addition of a small amount of yttria (for example 0.5%) significantly strengthens the ceria. The yttria modified ceria is useful as a thermal barrier coating.

Abstract: A gas turbine engine combustor liner with improved high temperature capability is achieved by embedding ceramic tiles into a fiber reinforced glass ceramic matrix composite substrate, so as to incorporate a space between the tiles and the substrate, the space serving to eliminate a direct heat conductive path between the tile and the substrate. The space is created by inserting a fugitive layer between the tiles and the substrate prior to compaction of the substrate, followed by removal of the fugitive layer. A fugitive material sprayed on the supportive region of the tiles prior to liner fabrication prevents the substrate material from bonding to the tiles, and prevents cracking of the tiles during temperature cycling.

Abstract: A method and apparatus for heat-treating nickel base superalloy articles to provide different properties in different regions of the article. An initially fine grain microstructure is heated such that a portion of the article is held above the .gamma.' solvus temperature long enough to provide a coarse grain microstructure while the remainder of the article remains below the .gamma.' solvus temperature and retains the fine grain microstructure. The coarse grain microstructure provides a reduced rate of fatigue crack growth rate while the fine grain microstructure retains good tensile properties. The invention is particularly applicable to the fabrication of turbine disks for gas turbine engines.

Abstract: A substantially microcrack- and blister-free composite can be made by drying an addition-type polyimide molding compound under suitable conditions to remove excess moisture. The molding compound includes a mixture of a polyimide resin and a plurality of carbon reinforcing fibers less than 3 mm long. The molding compound is placed into a heated material reservoir and transferred to a heated molding tool with a heated transfer ram. The ram establishes a molding pressure in a mold cavity in the molding tool sufficient to cure the molding compound into the desired composite. The molding compound is transferred to the mold cavity such that the molding compound is heated to a molding temperature at a rate of at least about 85.degree. C./min. The molding pressure and temperature are maintained in the mold cavity for a time sufficient to cure the molding compound into the desired composite.

Abstract: Superalloy castings having large variations in section thickness are heat treated using a cyclic stress relief procedure, with the temperature being cycled between about 50.degree. F. (28.degree. C.) and 150.degree. F. (83.degree. C.) below the second phase particle solvus temperature, to relieve the residual stresses incurred during cooling within the mold following casting, followed by a solution cycle at a temperature about 25.degree. F. (14.degree. C.) below the second phase particle solvus temperature to dissolve some or all of the second phase particles.

Abstract: A method for removing a predetermined amount of material from the inner surface of a circular article which deviates from a true circular configuration. The outer surface of the article is touch probed to determine its true location in space, and the data are stored in a computer memory. These data are then compared to engineering design data to establish the location of the surface to which material removal is desired. A control computer compares the measured data with the design data, and sends commands to the machine control system, causing the machine to remove the excess material down to the desired dimension. Any deviations from circular are compensated for by moving the article radially relative to the cutting tool as the article moves circumferentially relative to the cutting tool.

Abstract: A method for casting metering holes connecting the inner and outer surfaces of hollow investment cast objects, such as hollow air cooled gas turbine airfoils. The method incorporates mini cores having metering hole pins which extend further into the inner cavity than the surface of the cavity, so that the ends of the holes can be exposed by a subsequent machining operation. The method also includes forming a wax pattern which avoids contact between the wax and the metering hole pins so that the pins are not broken by the wax during the heatup portion of the wax removal step after formation of the ceramic casting mold.

Abstract: During the manufacturing process for turbine blades and vanes, among other hollow articles, the hollow cavities can become contaminated. Removal of the contaminants is a tedious, time consuming process which commonly results in component rework or rejection. Introducing a foam filler into the hollow cavities, prior to manufacturing, prevents contamination; enhancing manufacturing efficiency and component integrity.