Abstract: An overcoat is applied over thermal barrier coatings such as YSZ or other columnar grain ceramic. The exposed surface of the TBC is prepared to ensure that it is clean and has a proper roughness. The surface is then heated and an overcoat material such as a solid solution of chromia and alumina is deposited on the exposed surface, for example by plasma spraying to form a continuous overcoat on the TBC. The overcoat is preferably corrosion and erosion resistant, and inhibits the migration of oxygen to the underlying TBC and alumina layer.

Abstract: The present invention relates to a thermal barrier coated article with spallation and delamination inhibiting metallic bond coat. The metallic bond coat contains a reactive element oxide, preferably yttria, which reacts with sulfur, typically migrating from the substrate to the thermal barrier coating, to prevent the sulfur from inducing spallation of the oxide scale at the interface of the thermal barrier coating and the metallic bond coat. This metallic bond coat is preferably multi-layered having a reactive element oxide containing layer sandwiched between two reactive element oxide-free layers.

Abstract: Single crystal superalloy castings are described which have excellent oxidation resistance. The oxidation resistance is due to the presence of small but effective amounts of magnesium in the casting. Single crystal castings containing magnesium in the range of 5-200 parts per million, by weight, are described.

Abstract: A corrosion inhibited fuel mixture includes a hydrocarbon fuel, at least one vanadium composition, and a yttrium composition. The concentration of the yttrium composition in the mixture provides at least a stoichiometric amount of yttrium for a substantially complete reaction between the yttrium and V.sub.2 O.sub.5 formed from the vanadium composition when the mixture is burned. The yttrium and V.sub.2 O.sub.5 react to form YVO.sub.4. One particular yttrium composition useful as a hydrocarbon fuel soluble, water stable vanadium corrosion inhibitor incorporates a yttrium ester having at least four carbon atoms and a hydrocarbon fuel soluble chelating agent that includes 2,4-pentanediene. The complex has a molar ratio of 2,4-pentanediene to yttrium of up to 5:1.

Abstract: Single crystal superalloy castings are described which have excellent oxidation resistance. The oxidation resistance is due to the presence of small but effective amounts of magnesium in the casting. Single crystal castings containing magnesium in the range of 5-200 parts per million, by weight, are described.

Abstract: Molybdenum disilicide base materials and methods for producing them are described. Mixtures of MoSi.sub.2 powder and other powders including SiO.sub.2, Si.sub.3 N.sub.4, SiC and Mo.sub.5 Si.sub.3 are plasma sprayed. Another embodiment which involves oxidation of MoSi.sub.2 is also disclosed. The resistant materials have particular utility as coatings for Nb alloys.

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: Thermomechanical fatigue failure in components in high performance gas turbine engines is diminished by providing the component with an overlay of a metallic coating and a strain isolating layer located between the surface of the component and the metallic coating overlay.

Abstract: According to this invention, the oxidation resistance of alumina scale forming nickel based superalloys is significantly improved by controlling the level of sulfur in the alloy composition. According to one preferred embodiment of the invention, the superalloys contain less than 5 parts per million, by weight, of sulfur. Most preferably, they contain less than 2 parts per million, by weight, of sulfur.

Abstract: A silver base electrical contact material is described which contains a dispersion of particles consisting of cadmium oxide and nickel. The nickel particles are surrounded by a continuous adherent coating of nickel oxide which eliminates the detrimental reaction which would otherwise occur between nickel and cadmium oxide. The invention contact materials have improved lives and are fabricated by any one of several different powder metallurgy techniques.

Abstract: A silver base electrical contact material is described which contains a dispersion of particles consisting of cadmium oxide and nickel. The nickel particles are surrounded by a continuous adherent coating of nickel oxide which eliminates the detrimental reaction which would otherwise occur between nickel and cadmium oxide. The invention contact materials have improved lives and are fabricated by any one of several different powder metallurgy techniques.

Abstract: A high speed method of producing continuous length magnet wire coated with a high solids content polymer coating composition. Copper or copper alloy wire segments are joined by brazing utilizing a braze whose melting point is greater than 1000.degree. F. and less than 1600.degree. F. The thus formed joint has a tensile strength greater than 27,000 p.s.i., and is capable of being conformed to the circumference of the wire substrate without substantially altering the surface integrity of the wire. The continuous length magnet wire is preheated to an elevated temperature. The preheated wire is coated with a noncirculating polymer enamel composition having a high solids content and a high viscosity at high speed. The enamel coated wire is then cured.

Abstract: The high temperature properties of protective coatings, paricularly the oxidation resistance, is improved by the melting of a surface portion of the coating using a high intensity energy source. The surface melting refines and homogenizes the coating structure, thereby eliminating defects which would otherwise cause premature coating failure.

Abstract: An improved hot dip coating of the zinc aluminum type contains germanium (Ge). In Zn-10Al coatings the addition of 0.1-1.2 Ge weight percent increases the fluidity of the molten metal in the bath and thereby enables substantially thinner coatings having more refined phase structure. Silicon (Si) is found to exhibit an analogous effect, but it not as powerful as Ge. Improved coatings contain zinc, 7-17Al, and 0.1-3(Ge+Si), where Ge ranges from 0-1.2, all weight percent.

Abstract: An article with an improved MCrAlY coating is disclosed wherein a plasma sprayed MCrAlY coating is provided with a metallic envelope and then hot isostatically pressed to densify the coating and interdiffuse the envelope. Thus, the substrate is provided with a coating which in its bulk is the densified plasma coating with an outer surface zone which is enriched in a metal which enhances the oxidation-corrosion protective properties of the coating. Preferred coatings have a standard CoCrAlY bulk with a metal-enriched surface zone of about 0.02 mm depth. When aluminum is added the surface zone is comprised by weight percent of about 60 Co, 20 Cr and 22 Al. With chromium the surface zone is about 50 Co, 43 Cr and 8.5 Al.

Abstract: The oxidation-corrosion resistance of plasma sprayed MCrAlY overlay coatings is improved. The coating method involves plasma spraying the MCrAlY coating alloy onto a superalloy substrate, applying a chromium or aluminum envelope over the outer surface of the coating or mechanically working the outer surface to seal the surface against penetration by the high pressure isostatic atmosphere to be subsequently applied and then hot isostatically pressing the coated substrate to close the coating defects and diffuse at least a portion of the envelope, if present, into the overlay coating. The invention thus can provide an MCrAlY coating not only substantially free of pores, voids and the like defects but also having at least an outer zone enriched in chromium, aluminum or like metals.

Abstract: A method for coating a nickel-base superalloy substrate with a nickel-aluminide coating, saturated with chromium and containing no precipitated phases is disclosed which comprises enriching the superalloy substrate with chromium by diffusion of chromium into the substrate at a rate below that at which a pure or alloyed chromium layer forms and then growing a nickel aluminide coating on the chromium enriched substrate surface by the outward diffusion of nickel from the substrate into an aluminum-containing pack in which the source of aluminum is the stoichiometric intermetallic compound NiAl, or a metal powder mixture having the overall aluminum activity of NiAl.

Abstract: A novel filament reinforced composite comprising a plurality of fibers selected from the group consisting of graphite fibers, amorphous carbon fibers and pyrolytic graphite fibers bonded together in an aluminide matrix, selected from the group consisting of nickel aluminide, cobalt aluminide and solutions and mixtures thereof, said composite having relatively high strengths at elevated temperatures.

Abstract: A corrosion inhibited fuel mixture includes a hydrocarbon fuel, at least one vanadium composition, and a yttrium composition. The concentration of the yttrium composition in the mixture provides at least a stoichiometric amount of yttrium for a substantially complete reaction between the yttrium and V.sub.2 O.sub.5 formed from the vanadium composition when the mixture is burned. The yttrium and V.sub.2 O.sub.5 react to form YVO.sub.4. One particular yttrium composition useful as a hydrocarbon fuel soluble, water stable vanadium corrosion inhibitor incorporates a yttrium ester having at least four carbon atoms and a hydrocarbon fuel soluble chelating agent that includes 2,4-pentanedi.?.e.!..Iadd.o.Iaddend.ne. The complex has a molar ratio of 2,4-pentanedi.?.e.!..Iadd.o.Iaddend.ne to yttrium of up to 5:1.