Dresser Industries, Inc.

Dow Corning Corporation

The Babcock & Wilcox Company

Northrop Grumman Systems Corporation

Coi Ceramics, Inc.

Daniel R Petrak

Gary Lee Stark

Thomas R Kleeb

Howard M Winkelbauer

Ke-Chin Wang

Richard E Jones

Robert A Petrisko

Gregg A Zank

Andrew Szweda

Philip L Berneburg

William E Lawrie

Todd J Bridgewater

Jae D Lee

Thomas Franklin Foltz

Jamal N Duqum

Kathryn W Grant

A method for producing ceramic matrix composites wherein the method has the steps of impregnating crystalline silicon carbide fibers coated with an interfacial coating with a ceramic matrix precursor; forming the impregnated fibers into the desired shape; curing the shape; and heating the cured shape to a temperature in the range of greater than 1450&deg; C. to 1800&deg; C. to convert the ceramic matrix precursor into a crystal containing ceramic. A densification step may be optionally carried out until the desired porosity/density of the ceramic matrix composite is achieved.

Method for producing ceramic matrix composites

This invention pertains to ceramic matrix composites that comprise the coated ceramic fibers wherein the coating comprises at least one binary coating of boron nitride (BN) and silicon nitride (Si N ) within ceramic matrices derived from curable preceramic polymers. The composites can be formed into complex shapes which have good oxidation resistance at high temperature, good resistance to moisture high flexural strength and are resistant to moisture.

Ceramic matrix composites

A method for changing the dielectric properties of a polymer impregnated and pyrolyzed ceramic matrix composite (polymer impregnated and pyrolyzed ceramic matrix composite) is disclosed. The polymer impregnated and pyrolyzed ceramic matrix composite can be used in aircraft and turbine engines. polymer impregnated and pyrolyzed ceramic matrix composite comprises a ceramic matrix, a reinforcing fiber, and at least 1 additive used to change dielectric properties (dielectric constant and loss factor). The additive can be a low dielectric constant material having a dielectric constant in the range of 1 to 7.5. The low dielectric constant material can be an oxide such as silica or aluminosilicate or a non-oxide such as silicon nitride, boron nitride, or silicon carbide. The low dielectric constant material can be incorporated in the ceramic matrix as a filler. The low dielectric constant material may be incorporated in a uniform array of holes fabricated in the polymer impregnated and pyrolyzed ceramic matrix composite.

Method for changing the dielectric properties of a ceramic matrix composite

Conductive and/or chemically absorptive ceramic fibers are woven with optional non-conductive/non-absorptive ceramic fibers to create a fiber reinforcement which is impregnated with a ceramic-material-producing (pre-ceramic polymer) binder and heated to create the ceramic honeycomb with controlled ohmic loss and/or chemical absorption properties. The desired properties of the honeycomb material can be provided by the conductive and/absorptive ceramic fibers alone or in combination with non-fibrous or fibrous conductive and/or absorptive ceramic material provided by the binder, typically a preceramic polymer which may or may not contain dispersed ceramic materials; after the honeycomb is formed, the non-fibrous or fibrous conductive and/or absorptive ceramic material is interspersed throughout the honeycomb. By heating the impregnated fiber reinforcement in the absence of oxygen, carbon from any carbon-containing materials within the binder remain as a part of the honeycomb material. The honeycomb can be loaded with additional carbon or carbon-containing fibers by repeating the loading and heating in the absence of oxygen steps. For applications requiring long-term thermo-oxidative resistance, refractory ceramics like pure silicon carbide can be substituted for the fibers or fillers employed.

High temperature electromagnetic radiation absorbent material and method

Ceramic honeycomb and method

Fiber reinforced ceramic matrix composites are prepared by coating refractory fibers having a interfacial coating thereon with a curable preceramic polymer having a char which contains greater than about 50% sealant oxide atoms followed by forming the coated fibers into the desired shape, curing the coated fibers to form a pre-preg, heating the pre-preg to form a composite and heating the composite in an oxidizing environment to form an in situ sealant oxide coating on the composite. The resultant composites have good oxidation resistance at high temperature as well as good strength and toughness.

Method for making ceramic matrix composites

The invention relates to silicon nitride composite articles having improved fracture toughness prepared by forming a composition including small amounts of boron nitride powder in a silicon nitride powder base and processing the composition.

Silicon nitride/boron nitride composite with enhanced fracture toughness

An ultrasonic transducer arrangement for inspecting a work piece at an elevated temperature through the use of ceramic delay lines is disclosed. The ceramic material utilized for the delay lines is comprised of a composition of silicon nitride and boron nitride which is hot pressed so that the boron nitride platelets are aligned substantially parallel to the propagation direction of the ultrasonic pulses thus minimizing pulse attenuation. The ceramic material is heat and wear resistant and can be machined so as to conform to the surface of the work piece being inspected.

Ceramic delay lines for hot ultrasonic examination

A ceramic fiber-reinforced ceramic heat exchanger includes a tube sheet and one or more coiled, oval cross-section U-tubes formed integrally with the tube sheet, wherein both the tube and tube sheet are composed of a ceramic fiber-reinforced ceramic composition, particularly suited for waste heat recovery in harsh flue gas environments.

Ceramic heat exchangers

A means for producing nitride bonded refractory shapes, in situ, by mixing an aluminum metal powder, relatively pure silica and a refractory aggregate. The mixes are pressed into shapes and burned at elevated temperatures in a nitriding atmosphere to form the bond.

Refractory

A means for producing nitride bonded refractory shapes, in situ, by mixing an aluminum metal powder, relatively pure silica, crude clay and a refractory aggregate. The mixes are pressed into shapes and burned at elevated temperatures in a nitriding atmosphere to form the bond.

Method of preparing a batch of non-basic refractory gunning mix for forming a refractory monolith on its situs of use by mixing non-basic refractory aggregate and calcium aluminate cement with from about 0.5 to 25%, on a cement basis, of calcium chloride hydrate and mixing the resulting batch with water to allow gunning.

Method of in situ fabrication of a monolithic refractory lining

This invention relates to refractory castables containing a heat resistant aggregate and calcium aluminate cement plus the addition of +35 mesh silicon carbide wherein such castable may be used at temperatures up to 3200.degree. F. with the required strength.

Growing community of inventors

Midland, MI, United States of America

Daniel R Petrak