Lanxide Technology Company, LP

Gerhard H Schiroky

Terry D Claar

William B Johnson

Christopher R Kennedy

John E Garnier

Birol Sonuparlak

Ali S Fareed

Michael K Aghajanian

Marc S Newkirk

Robert C Kantner

Michael A Rocazella

Gregory E Hannon

Allyn L McCormick

Danny R White

Ratnesh K Dwivedi

Kevin P Pochopien

James C Wang

Donald P Ripa

John T Burke

Vilupanur Alwar Ravi

Jerry G Weinstein

Eugene S Park

Steven D Keck

Philip J Roach

Virgil Irick, Jr

Dennis James Landini

Coated ceramic filler materials comprised of ceramic particles, fibers, whiskers, etc. having at least two substantially continuous coatings thereon are provided. The coatings are selected so that the interfacial shear strength between the ceramic filler material and the first coating, between coatings, or between the outer coating and the surrounding matrix material, are not equal so as to permit debonding and pull-our when fracture occurs. The resultant, multi-coated ceramic filler materials may be employed to provide composites, especially ceramic matrix composites, with increased fracture toughness. The ceramic filler materials are designed to be particularly compatible with ceramic matrices formed by directed oxidation of precursor metals, but such ceramic filler materials are also adaptable for use in many other composite material systems. In a preferred embodiment, the coatings are applied to the ceramic fiber plies or preforms by CVD. Accordingly, coating depositions which are more uniform through the preform cross-section have been achieved by assembling the preform with exterior fabric plies having greater gas permeability than the fibrous preform or fabric plies located deeper in the preform interior. In another preferred embodiment, at least one additional filler material different in some respect from a first fibrous filler material is provided to the permeable mass to be infiltrated with matrix material. Specifically, the additional filler material is provided for the purpose of tailoring at least one additional property of the self-supporting composite body to be formed not already tailored by the first fibrous filler material.

Composite materials and methods for making the same

Method for in situ tailoring the component of ceramic articles

The present invention relates to a novel process for forming thin metal matrix composite bodies. Particularly, an infiltration enhancer and/or an infiltrating atmosphere are in communication with a filler material or preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform. Such spontaneous infiltration occurs without the application of any pressure or vacuum. In an embodiment of the present invention, the filler material may be sprayed upon a thin sheet of matrix metal. Alternatively, the filler material may be shaped via tape casting, slip casting, etc. to provide a thin preform. In another embodiment of the present invention, a body of matrix metal may be coated with a filler material such that upon spontaneous infiltration a metal matrix composite body is produced which inversely replicates the configuration of the original body of matrix metal. In yet another embodiment of the present invention, a plurality of thin tape cast preforms which are segregated by a barrier material (e.g., graphite foil) may be infiltrated with a matrix metal during a single spontaneous infiltration process.

Methods for making thin metal matrix composite bodies and articles

The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials in composite bodies. In a preferred embodiment of the invention, a coated ceramic filler material adaptable for use as a reinforcing component in a ceramic matrix composite is provided with a plurality of superimposed coatings. The coating system includes a first coating in substantially continuous contact with the ceramic filler material and one or more additional or outer coatings superimposed over the underlying coating and in substantially continuous contact therewith. Zonal junctions are formed between the filler and the first coating, between superimposed coatings, and between the outer coating and the ceramic matrix. The coatings are selected so that the interfacial shear strength of at least one of these several zones is weak relative to the other zones. Upon the application of fracture stress to the composite, the weak zone allows for debonding of the filler before the filler fractures, and pull-out or shear of the filler upon fracture of the filler. This debonding and friction pull-out enhances certain mechanical properties of the composite, and in particular, debonding improves the fracture toughness.

The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the matrix such that any desirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. Ceramic filler materials which serve as reinforcements may have a plurality of super-imposed coatings thereon, at least one of which coatings may function as a getterer. The coated materials may be useful as reinforcing materials in ceramic matrix composites to provide improved mechanical properties such as fracture toughness. The present invention also relates to improved composites which incorporate these materials, and to their methods of manufacture.

The present invention relates to a novel method for forming metal matrix composite bodies. Particularly, a permeable mass of filler material is formed into a preform. The preform material can then be placed onto the surface of or into a matrix metal alloy, whereupon the matrix metal alloy spontaneously infiltrates the preform. After substantial complete infiltration of the preform, the preform begins to at least partially sink into the matrix metal alloy supply. The depth to which the preform may sink into the molten matrix metal alloy is controlled by utilizing a support means. The support means prevents the preform being infiltrated from submerging completely beneath the surface of the matrix metal alloy supply. The matrix metal which has infiltrated the preform is then allowed to cool, thus forming a metal matrix composite body.

Flotation process for the formation of metal matrix composite bodies

Thin metal matrix composites and production methods

Method for forming bodies by reactive infiltration

This invention relates generally to a novel method of manufacturing a composite body, such as a ZrB.sub.2 --ZrC--Zr (optional) composite body, by utilizing a post-treatment process and to the novel products made thereby. More particularly, the invention relates to a method of modifying a composite body comprising one or more boron-containing compounds (e.g., a boride or a boride and a carbide) which has been made by the reactive infiltration of a molten parent metal into a bed or mass containing boron carbide, and optionally one or more inert fillers, to form the body.

Method of modifying ceramic composite bodies by a post-treatment process

Additives for property modification in ceramic composite bodies

Joining methods for ceramic composite bodies

This invention relates generally to a novel method of preparing self-supporting bodies, and novel products made thereby. In its more specific aspects, this invention relates to a method for producing self-supporting bodies comprising one or more boron-containing compounds (e.g., a boride or a boride and a carbide, etc.) by reactive infiltration of molten parent metal into a preform comprising boron carbide or a boron donor material combined with a carbon donor material and, optionally, one or more inert fillers, to form the body. Specifically, a boron carbide material or combination of a boron donor material and a carbon donor material, and in either case, optionally, one or more inert fillers, are sedimentation cast, spray coated, tapped, slip cast, pressed, etc., onto or into a body and into a particular desired shape.

Method of producing ceramic composite bodies

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Hockessin, DE, United States of America

Gerhard H Schiroky