Southwest Research Institute

Other

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

Electric Power Research Institute Incorporated

Osaka Gas Company Limited

Partha P Paul

Stuart T Schwab

Richard J Martin

Ryoichi Nishida

Bradley L Edgar

Narayana Sastry Cheruvu

Niraj Vasishtha

Gerald R Leverant

Dorriah L Page

David L Ciminelli

The present invention provides a method for making a ceramic matrix composite comprising forming an infiltrated fiber reinforcement by infiltrating a plurality of plies of a fibrous material with a precursor polymer which decomposes to a substantially pure product selected from the group consisting of a refractory metal carbide and a refractory metal boride, and exposing the infiltrated fiber reinforcement to conditions effective to cure the precursor polymer and to decompose the precursor polymer to said substantially pure product.

Methods for making ceramic matrix composites using precursor polymers to refractory metal carbides and metal borides

The present invention provides a method for making a high temperature coating comprising applying to a surface a precursor polymer which decomposes to a product selected from the group consisting of a refractory metal carbide and a refractory metal boride, and exposing the precursor polymer to conditions effective to decompose the precursor polymer to the product.

Methods for making high temperature coatings from precursor polymers to refractory metals carbides and metal borides

The present invention provides a method for producing precursor polymers which decompose to a substantially pure refractory metal carbide or refractory metal boride. The method comprises mixing a transition metal compound with either (a) an organometallic, or (b) a backbone polymer comprising a plurality of unsaturated carbon-carbon bonds. The mixing occurs under conditions effective to form organo-transition metal complexes The organometallic (a), comprises either a borane, a carborane, or an organometallic comprising a metal and at least one unsaturated carbon-carbon bond. When an organometallic (a) is used, the transition metal complexes must be polymerized to form the precursor polymers. When a backbone polymer (b) is used, the transition metal complexes, themselves, comprise the precursor polymers. The refractory metal carbides or metal borides formed upon decomposition of these precursor polymers may be used to make ceramic matrix composites and high temperature coatings.

Precursor polymers to refractory metal carbides and metal borides

Controlled and thorough stabilization of pitch is provided by incorporating an oxidant into the pitch. In one embodiment of the invention, the oxidant is intimately mixed with the pitch. In another embodiment, the oxidant is encapsulated in a suitable encapsulant and the encapsulated oxidant is intimately mixed with the pitch. This material is particularly useful in the preparation of a carbon-carbon composite, but is also useful for preparing fibers and solid preforms.

Encapsulation of oxidants for pitch stabilization

An integrated oxidation-reduction process whereby a thermal oxidation zone and a NOx reduction zone are incorporated into a single device. A thermal oxidation and catalytic reduction system having a multi-spiral, heat recuperative configuration and including a lean NOx catalytic section disposed in the low-temperature regions is disclosed, as is a corresponding method. The catalyst may be disposed on the oxidizer walls or on a matrix of porous inert media disposed in the spiral passages of the oxidizer. A film-injection technique to selectively provide reactants to the catalyst surface is also disclosed. The catalyst may be limited to a concave portion of a sidewall to diminish boundary layer separation of the reactants.

Devices for reducing emissions, and methods for same

A method of repairing a damaged area of a thermal barrier coating on a component which is subjected to a hostile thermal environment, which comprises cleaning the damaged area, applying a partially stabilized zirconium sol-gel to the area, and pyrolizing the sol-gel to form a TBC repair layer.

Method of repairing a thermal barrier coating

Method for making ceramic matrix composites using precursor polymers to

The present invention provides a method for making a high temperature coating comprising applying to a surface a precursor polymer which decomposes to a substantially pure product selected from the group consisting of a refractory metal carbide and a refractory metal boride, and exposing the precursor polymer to conditions effective to decompose the precursor polymer to said substantially pure product.

Methods for making high temperature coatings from precursor polymers to

Alkoxides with polymerizable groups are single source precursors for organic-inorganic hybrid composites possessing good mechanical properties. Additional function groups of the alkoxides provide enhanced adhesion to other surfaces, such as dentin. The selection of specific organic monomers having functional groups that are responsible for enhanced properties of the organic-inorganic hybrid composites is important. Single source precursors containing the desired functional groups are condensed and polymerized into the organic-inorganic hybrid composites with enhanced properties which are particularly useful as dental composites.

Organic-inorganic hybrid composites for dental restorative material

A hydrocarbon-independent lean-burn NO.sub.x catalyst for treatment of products of combustion includes a porous support impregnated with two transition metals. The first transition metal has a stable upper oxidation state that is reducible to a lower oxidation state in the presence of carbon monoxide which is oxidized in the presence of the first transition metal to form carbon dioxide. The second transition metal has a stable lower oxidation state and is capable of being raised to a higher oxidation state in the presence of NO.sub.x which is reduced to nitrogen and oxygen in the presence of the second metal. The first and second metals cooperate to form a redox reaction system which regenerates the active form of the catalyst by raising the first metal to its stable oxidation state and reducing the second metal to it stable lower oxidation state by electron transfer between the first and second metals. The catalyst is based on transition metals which are less expensive than the noble metal-containing catalysts in current use.

Metal complex derived catalyst and method of forming

There is disclosed a method of making polysilanes by polymerization of a silane in the presence of a catalyst comprising a phosphine-stabilized polyhydride of an early transition metal of Groups 4 to 7 of the Periodic Table and the resultant polysilanes which have a molecular weight higher than 1,000 and a polydispersity below about 2.

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San Antonio, TX, United States of America

Partha P Paul