Goodrich Corporation

The B. F. Goodrich Company

United States of America As Represented by the Secretary of the Air Force

Edward Roy Stover

Robert Bianco

Anthony M Mazany

Sai-Kwing Lau

Thomas Dwayne Nixon

Salvatore J Calandra

Vijay V Pujar

Mark J Purdy

Gary L Clark

Lanny Dean Ritz

Robert J Price

Larry D Bentson

Robert P Dietz

Steve T Keller

A method of inhibiting oxidation of a porous carbon-carbon composite is disclosed and comprises the steps of: (a) contacting the carbon-carbon composite with an oxidation inhibiting composition comprising phosphoric acid or an acid phosphate salt, at least one aluminum salt, and at least one additional metal salt, the oxidation inhibiting composition penetrating at least some of the pores of the carbon-carbon composite; and (b) heating the carbon-carbon composite at a temperature sufficient to form a deposit from the oxidation inhibiting composition within at least some of the penetrated pores of the carbon-carbon composite. The foregoing oxidation inhibiting composition and carbon-carbon composites treated by the foregoing method are also disclosed.

Oxidation inhibition of carbon-carbon composites

This invention relates to a method of inhibiting oxidation of a porous carbon-carbon composite comprising the steps of: (a) contacting the carbon-carbon composite with an oxidation inhibiting composition comprising phosphoric acid or an acid phosphate salt, at least one aluminum salt, and at least one additional metal salt, the oxidation inhibiting composition penetrating at least some of the pores of the carbon-carbon composite; and (b) heating the carbon-carbon composite at a temperature sufficient to form a deposit from the oxidation inhibiting composition within at least some of the penetrated pores of the carbon-carbon composite. The invention also relates to the foregoing oxidation inhibiting composition. The invention relates to carbon-carbon composites treated by the foregoing method.

The present invention is a composite material, a process and a product formed by the process. The composite is formed by a process that includes forming a fibrous structure comprising fibers into a preform, coating the fibers of the fibrous structure preform with elemental carbon to impregnate that preform, infiltrating the preform with boron carbide to form an impregnated green body. The impregnated green body is infiltrated with liquid naphthalene or other carbon precursor, which is thereafter pyrolyzed to form a carbon char. Then, the char infiltrated green body is infiltrated with molten silicon to form a continuous matrix throughout the composite. The silicon in the continuous matrix is reacted with the carbon char to form silicon carbide.

Boron carbide based ceramic matrix composites

The present invention is a composite material and process to produce same. That material comprises a fibrous structure which is initially predominantly coated with elemental carbon; that fibrous structure is then subsequently predominantly coated with at least one ceramic material, e.g., boron carbide, which is non-reactive with silicon. The composite material also comprises a silicon matrix which is continuous and predominantly surrounds the fibrous structure, which has been initially predominantly coated with elemental carbon and subsequently predominantly coated with at least one ceramic material. The matrix which has a fine grain crystalline structure of predominantly 20 microns or less in size. The at least one ceramic material is discontinuous within that matrix. The fibrous material pulls out of the elemental carbon, which initially predominantly coats that fibrous structure, when the composite is subjected to fracture.

This invention relates to a method of inhibiting catalyzed oxidation of carbon-carbon composites involving the steps of treating a carbon-carbon composite having pores with a liquid composition, preferably an aqueous solution, containing (a) phosphoric acid, (b) a zinc salt, and (c) an aluminum salt and heating the treated carbon-carbon composite to a temperature sufficient to form deposits within the pores. In one aspect, the deposit comprises a dispersion of aluminum-rich phosphate in zinc-rich phosphate. This solution may be used in combination with a silicon carbide barrier coating, applied by either painting or by CVD, to allow application at higher temperatures. The adherence of the barrier coating may be improved by preoxidizing the surface to increase porosity at the surface. Articles, including friction brakes, and the aqueous compositions are also part of this invention. The methods and articles show improved penetration and retention of the catalyzed oxidation inhibitors.

Methods of inhibiting catalyzed oxidation of carbon-carbon composites using phosphoric acid, a zinc salt, and an aluminum salt and articles made therefrom

This invention relates to a composition and method of inhibiting catalyzed oxidation of carbon-carbon composites. The invention includes compositions, capable of impregnating carbon-carbon composites. The invention also includes a method of inhibiting catalyzed oxidation of carbon-carbon composites comprising the steps of treating a carbon-carbon composite with the catalyzed oxidation inhibiting aqueous mixture, and heating the treated carbon-carbon composite to a temperature sufficient to remove water. Articles, including friction brakes, made by this method are also part of this invention. Brake lugs, and other exposed areas of aircraft braking systems have improved resistance to catalyzed oxidation.

Method of inhibiting catalyzed oxidation of carbon-carbon composites

This invention relates to a composition and method of inhibiting catalyzed oxidation of carbon-carbon composites. The invention includes compositions, capable of impregnating carbon-carbon composites, comprising an aqueous mixture of (a) phosphoric acid, (b) a metal phosphate, and (c) a penetration and retention improving amount of a compatible wetting agent selected from the group consisting of polyols, alkoxylated monohydric alcohols, and mixtures thereof. The invention also includes a method of inhibiting catalyzed oxidation of carbon-carbon composites comprising the steps of treating a carbon-carbon composite with the catalyzed oxidation inhibiting aqueous mixture, and heating the treated carbon-carbon composite to a temperature sufficient to remove water. Articles, including friction brakes, made by this method are also part of this invention. Treated brake lugs, and other exposed areas of aircraft braking systems have improved resistance to catalyzed oxidation.

Inhibition of catalyzed oxidation of carbon-carbon composites

Carbon/carbon composites including those structures formed from a fibrous reinforcement itself formed principally from carbon in a carbon matrix are protected against oxidation by multi-layer sealant system preferably including a multi-layer paint including in its carbonized binder refactory granules and inhibitor particles that form a moisture resistant, viscosity-stabilized borate glass when exposed to a high-temperature, oxidizing environment, and an outer ceramic shell formed by CVI/CVD in situ formation of boron carbide followed by silicon carbide. The paint is prepared by mixing finely divided powders of borate precursor compounds or borate glass frit and refractory granules with a carbon char yielding precursor binder such as phenolic resin or pitch which preferably produces a highly porous structure upon carbonization.

Moisture and oxidation resistant carbon/carbon composites

The structure comprises four groups of elongated rectilinear elements, with the elements of each group parallel to one another. The elements of three of the groups are mutually orthogonal and the elements of the other group are disposed diagonally to the elements of two of the three mutually orthogonal groups. The structure is useful for fabricating nosetips for maneuvering re-entry vehicles.

Four-directional structure for reinforcement

A fine textured, high density, three directional, carbon-carbon fiber composite material with an axially to laterally oriented fiber ratio of 1.5 to 1 or higher and a density of 185 g/cm.sup.3 or higher.

Growing community of inventors

Akron, OH, United States of America

Edward Roy Stover