Abstract: An aqueous phosphoric bonding solution consists essentially of phosphoric acid, a source of magnesium ions, and a leachable corrosion inhibitor. The bonding solution is stable with respect to inorganic metal particles, such as aluminum, which are admixed to the bonding solution for the preparation of a coating slurry. Metal parts coated with the coating compositions have very satisfactory properties such as heat and corrosion resistance.

Abstract: Method for localized aluminide coating applied for the first time or as repair includes creating a contained space by disposing coating material comprising an aluminum source and a halide activator at least partially over and in an out-of-contact relation with a target surface of a metal substrate. Heating the substrate to a temperature to cause the aluminum source to react with the halide activator and the substrate results in diffusion aluminide coating of the targeted surface. An article comprising a target surface of a metal substrate, said surface bounding a contained space, and a coating tape comprising an aluminum source and a halide activator and disposed in an out-of-contact relation at least partially over the contained space whereby, when the substrate is heated to a temperature to cause the halide activator to react with the aluminum source, a diffusion aluminide coating is formed on the target surface.

Abstract: A substrate protected by a polymeric lining wherein passageways are provided between the lining and the substrate for channeling of fluids which may penetrate through the lining to the substrate surface. In one embodiment the lining is formed to provide for passages between the lining and the substrate. Mesh attached to the substrate provides for securement of the lining to the substrate by at least partial embedment of the mesh within the lining. Wire spacers are positioned between the mesh and the substrate to separate portions of the lining from the substrate surface and form passageways for channeling fluid which may penetrate the lining. In another embodiment a vessel includes a network of spacers forming a generally parallel array of passageways and at least one passageway transverse to the parallel array of passageways.

Abstract: Method for localized aluminide coating applied for the first time or as repair includes creating a contained space by disposing coating material comprising an aluminum source and a halide activator at least partially over and in an out-of-contact relation with a target surface of a metal substrate. Heating the substrate to a temperature to cause the aluminum source to react with the halide activator and the substrate results in diffusion aluminide coating of the targeted surface. An article comprising a target surface of a metal substrate, said surface bounding a contained space, and a coating tape comprising an aluminum source and a halide activator and disposed in an out-of-contact relation at least partially over the contained space whereby, when the substrate is heated to a temperature to cause the halide activator to react with the aluminum source, a diffusion aluminide coating is formed on the target surface.

Abstract: A process for diffusion bonding of cracks and other gaps in high-temperature nickel and cobalt alloy components is described. The gap is filled with alloy powder matching the substrate alloy, or with an alloy of superior properties, such as MAR-M 247, MAR-M 247LC, or CM 247LC. A braze containing a melting point depressant is either mixed into the alloy powder or applied over it. The depressant is preferably hafnium, zirconium, or low boron. The component is heated for 15-45 minutes above the melting point of the braze, which fills the spaces between the alloy powder particles. The component is diffused at a temperature above or below the liquidus of the braze and solution heat-treated and aged at a temperature at which the braze and alloy mixture in the gap is solid, but the depressant diffuses away.

Abstract: Slurry coating compositions are provided for metal substrates, particularly nickel or cobalt-containing alloys, that enable inward-type diffusion aluminide coatings having a substantially uniform coating thickness to be formed thereon. Substantially uniform coating thicknesses are achieved independent of applied slurry composition thickness or application method. The slurry coating composition of the invention comprises a Cr—Al alloy containing about 50 wt % to about 80 wt % Cr in the alloy, LiF in an amount greater than or equal to 0.3 wt % of the Cr—Al alloy, an organic binder, and a solvent.

Abstract: A method of coating a substrate is provided. A metallic layer comprising at least about 8% nickel is deposited by thermal spraying on a substrate. The metallic layer has an average density greater than about 80%. A slurry layer comprising from about 10% to about 90% aluminum or alloy thereof is deposited on the metallic layer. Heating to a temperature in excess of 500° C. (932° F.) results in the formation of an intermetallic layer of NiAl. The resulting coating is particularly suited for protecting the surfaces of incinerators or other combustion chambers.

Abstract: A heat curable bonding composition for providing a coating to a solid substrate comprises water, phosphate ions, borate ions, and aluminum ions. The bonding composition has a pH in the range from about 1.4 to about 2.2, and is substantially free of chromate ions, molybdate ions, and magnesium ions.

Abstract: A heat curable bonding composition of the present invention comprises an aqueous solution containing phosphate ion (PO4−3) and chromium(III) ion (Cr+3, or trivalent chromium) and is substantially free of hexavalent chromium ions. The bonding composition may further contain at least one secondary cationic species. The bonding composition has a pH in the range of about 1 to about 3.5.

Abstract: A coated aerospace aluminum alloy part, such as a lipskin of a nacelle or a leading edge of a wing or tail, is disclosed which part is protected from corrosion due to severe environmental stresses, including high and low temperatures, and rain drop erosion, by a multilayer coating comprising a phosphate bonded metal containing basecoat and a resin based topcoat. A method of coating the part is disclosed.

Abstract: A method for coating turbomachinery having a metal surface to prevent fouling, the steps of the method being applying to the surface a first slurry containing an acidic aqueous medium containing galvanically active material and phosphate ions, thereby forming a galvanically sacrificial first layer, curing the first layer, applying to the cured first layer an aqueous non-conductive second slurry containing inorganic phosphate or silicate ions, thereby forming a non-conductive second layer, curing the second layer, applying to the cured second layer a liquid sealer composition containing a thermally stable organic polymer and fluorocarbon, thereby forming a top layer, and curing the top layer.

Abstract: An aqueous phosphoric bonding solution and coating composition slurry which are environmentally friendly in that they are generally free of molybdate or chromium. Yet the solution is stable with respect to inorganic metal particles, especially aluminum which are admixed to the bonding solution for the preparation of the coating slurry. The metal coated parts and the method of coating the parts with the coating composition are also described. The parts have very satisfactory properties.

Abstract: An improved aluminide coating especially for superalloy substrates. Slurry coating compositions of eutectic metal alloy powders and of non-eutectic metal powders, including an elemental powder of a silicide-former in a heat-curable liquid binder. A process for coating the substrates and the coated metal parts. The coatings have improved resistance to developing cracks and to hot corrosion and oxidation.

Abstract: Slurry coating compositions are provided for metal substrates, particularly nickel or cobalt-containing alloys, that enable inward-type diffusion aluminide coatings having a substantially uniform coating thickness to be formed thereon. Substantially uniform coating thicknesses are achieved independent of applied slurry composition thickness or application method. The slurry coating composition of the invention comprises a Cr--Al alloy containing about 50 wt % to about 80 wt % Cr in the alloy, LiF in an amount greater than or equal to 0.3 wt % of the Cr--Al alloy, an organic binder, and a solvent.

Abstract: A bonding composition for a heat curable overlay coating for coating a substrate is provided. The bonding composition comprises phosphate ions, permanganate ions, at least one species of metal cation having a valence greater than +1, and water. The bonding composition has a pH in the range from about 1.5 to about 4.5 and is substantially free of chromate ions and molybdate ions. Preferably, the molar ratio of phosphate ions to permanganate ions in the bonding composition is in the range from about 2:1 to about 580:1 and the nonvolatile content of the bonding composition is in the range from about 10% (wt) to about 35% (wt). Aluminum ions are a preferred species of metal cation in the bonding composition. Overlay coating compositions are also provided containing metallic aluminum particles dispersed in the bonding composition of the invention.

Abstract: A method for removing surface layers of a metal coating is disclosed. The method comprises applying an aluminum containing slurry to the surface of the metal coating, melting and diffusing the aluminum to form an aluminide layer within the surface of the metal coating, and removing the aluminide layer.

Abstract: A strain tolerant ceramic coating, preferably for use as an abrasive coating on a substrate is provided. The coating is prepared from a yttria and zirconia powder having an average particle size less than 40 microns. The coating is formed by depositing the powder on the substrate by a plasma spray process. The as-applied coating contains essentially no macrocracks, but a post-stressed coating contains a random distribution, population, and orientation of microcracks and macrocracks.

Abstract: A heat curable protective coating composition for providing barrier protection to a solid substrate. The coating composition comprises an aqueous solution of phosphate ions and nitrate ions and at least one species of metal ion having a valency greater than +1. The metal ions may be selected from the group consisting of aluminum ions, manganese ions, magnesium ions, cerium ions, cobalt ions, chromium(III) ions, nickel ions, iron ions, copper ions, and zinc ions. The composition has a pH in the range from about 0.5 to about 3.5. The composition is substantially free of chromate ions and molybdate ions. A cured topcoat is substantially clear and has a glossy appearance.

Abstract: A spray booth includes an outer enclosure in which the temperature and humidity of a fluid (such as air) is not controlled and a fluid handling unit within this enclosure, which circulates and controls the temperature and humidity of a smaller volume of the same fluid (air) to develop an environment suitable for application of coatings to desired substrates. In use, fluid is drawn from the outer enclosure into the inner, fluid handling unit in order to clean and modify the temperature and humidity of the fluid being handled, conditioning it to be delivered to the region of limited size which is established for receiving the substrate to be coated.

Abstract: The oxidation and corrosion resistance of a nickel-base alloy are enhanced by a process which includes first enriching the surface of an alloy substrate with platinum, as by electrolytic deposition, and then simultaneously diffusing aluminum and silicon from a molten state into the platinum-enriched substrate. The invention further provides coatings and coated substrates with enhanced oxidation and corrosion resistance.