Northrop Grumman Systems Corporation

Grumman Corporation

Northtrop Grumman Corporation

Steven Donald Atmur

Thomas Edward Strasser

Philip Shacter

Michael James Hagen

William Scott Richardson

Mark William Bland

A method of fabricating a discontinuous-fiber, ceramic matrix green-state composite component. The method includes preparation of a mixture of discontinuous fibers, in a quantity equal to about 100% of a desired end-product fiber quantity thereof, and a polymer-derived ceramic precursor resin in an excess quantity greater than about 150% of a desired end-product resin quantity thereof. The mixture so prepared then is introduced into a cavity of a molding tool and a vacuum is applied to the cavity through a vacuum aperture leading from the cavity. The mixture is drawn toward the vacuum aperture and consequently compacts a quantity of fibers within the cavity at the aperture site such that the fibers function as a filter to efficiently retain within the cavity fibers within the original mixture while removing under vacuum the excess resin that provided an effective vehicle for carrying and dispersing the discontinuous fibers. Finally, the molding tool is heated to a temperature and for a time sufficient to cure the resin/fiber mixture within the cavity and thereby fabricate the green-state composite component in a structurally sound manner.

Method of fabricating ceramic matrix composites employing a vacuum mold procedure

A fracture-resistant, thermally stable intake or exhaust valve for an internal combustion (IC) engine. The valve has a stem portion and a head portion, both of which are formed of fiber reinforced ceramic matrix composite (FRCMC) material. This FRCMC material generally includes a polymer-derived ceramic resin in its ceramic state, fibers, and filler materials. Employing FRCMC material to form the valve is advantageous as FRCMC material is highly temperature resistant and temperature stable, thereby allowing for increased engine operating temperatures. FRCMC material is also ductile, thus making the valve fracture resistant. The FRCMC material is also flaw-insensitive in that any flaw within the structure of the valve will not result in cracking and failure. In addition, FRCMC valves are considerably lighter than the existing metal valves. This provides an opportunity to reduce the weight of the overall valve train, thereby increasing engine performance. The addition of certain filler materials allows the FRCMC material to be tailored to exhibit a desired degree of harness and/or a desired coefficient of friction. Increasing the hardness of the head of the valve allows it to better withstand the violent environment of the engine cylinder, and lowering the coefficient of friction facilitates the valve movement within the engine.

Fiber reinforced ceramic matrix composite internal combustion engine intake/exhaust valves

An integrated, layered armor structure having multiple layers which alternate in their exhibited characteristics between extremely hard and ductile. The extremely hard layers of the armor structure are designed to shatter an impacting projectile, or pieces thereof, and to fracture in such a way as to dissipate at least a portion of the kinetic energy associated with the projectile pieces and to disperse the projectile pieces and hard layer fragments over a wide area. The ductile layers of the armor structure are designed to yield under the force of impinging projectile pieces and hard layer fragments from an adjacent hard layer. This yielding dissipates at least a portion of the remaining kinetic energy of these pieces and fragments. Pieces and fragments not possessing sufficient kinetic energy to tear through the ductile layer are trapped therein and so stopped.

Fiber reinforced ceramic matrix composite armor

Structural ceramic matrix composite material to be employed as automotive engine parts and the like is provided with erosion-resistant qualities in several ways. For one, an erosion-resistant material is applied to the surface as by plasma spraying. The erosion-resistant material can also be mixed with the fibers of the material, particularly near the surface.

Reducing wear between structural fiber reinforced ceramic matrix composite automotive engine parts in sliding contacting relationship

A heat-resistant, thermally insulative, ductile turbocharger housing for an internal combustion engine having a structure comprised at least partially of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. The material, being for the most part ceramic, provides the heat-resistance and thermal insulating capabilities of the FRCMC material, while the fibers produce a desired degree of ductility in the FRCMC material.

Method for forming a ceramic matrix composite turbocharger housing

A fiber-reinforced ceramic matrix composite (FRCMC) structure exhibiting tailored characteristics such as ductility, hardness, and coefficient of friction. Generally, this tailoring involves incorporating fibers into the composite in sufficient quantities to produce a certain degree of ductility, and if desired, incorporating filler material into the composite in sufficient quantities to produce a desired degree of other characteristics such as hardness and coefficient of friction. In both cases, the degree to which these respective characteristics are exhibited varies with the percent by volume of fibers and filler materials incorporated into the structure. Additionally, the degree to which these respective characteristics are exhibited varies with the form of fibers used (i.e., continuous or non-continuous) and with type of filler material employed. Thus, the tailoring of the characteristics exhibited by a FRCMC structure specifically involves selecting the quantity and form of the fibers that will produce the desired ductility, and selecting the amount and types of filler material that will produce the desired hardness and/or coefficient of friction in the FRCMC material.

Ceramic composite materials having tailored physical properties

A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed. This entails positioning the port liners within a mold designed to form the metal head in locations corresponding to the intake and exhaust ports of the head. Then, the mold is filled with molten metal to form the head with the port liners being integrally cast therewith.

Fiber reinforced ceramic matrix composite internal combustion engine

A pollutant-reducing catalytic converter for an internal combustion engine. The catalytic converter is of ceramic and operates at higher temperatures for increased efficiency. A ceramic foam is used as the substrate for the catalyst. The foam is an open-celled foam and the substrate is deposited on the walls of the cells. Thus, there is a maximum area of catalyst with a minimum amount of catalyst required. The catalytic converter can be placed in the engine compartment adjacent the engine for maximum efficiency without causing temperature problems within the engine compartment.

Ceramic catalytic converter

A heat-resistant, thermally stable, ductile piston ring for an internal combustion engine having a structure comprised at least partially of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic state and fibers. The ceramic portion of the material for the most part provides the heat-resistance of the FRCMC material, while the fibers produce a desired degree of ductility in the FRCMC material. Filler materials may incorporated into the piston ring to produce the desired degree of hardness and/or coefficient of friction.

Fiber reinforced ceramic matrix composite piston ring

An integrated brake pad and back plate having a brake pad section formed from a first fiber reinforced ceramic matrix composite (FRCMC) material and a back plate section formed from a second FRCMC material. The brake pad and back plate are integrated because the sections are molded together to form an integral, unitary structure. The first FRCMC material used in the brake pad section includes a pre-ceramic resin in its ceramic state, fibers and possibly a filler material. The types and amount of these constituents are generally chosen so as to impart characteristics desirable in brake pads, such as high temperature and erosion resistance, and a high coefficient of friction. The second FRCMC material used in the back plate section includes a pre-ceramic resin in its ceramic state and fibers. In this case, the types and amounts of the constituents making up the second FRCMC material are generally chosen to impart the strength to the back plate section necessary to withstand compressive and bending forces placed upon it during braking.

Integrated fiber reinforced ceramic matrix composite brake pad and back

A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends. It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed. This entails positioning the port liners within a mold designed to form the metal head in locations corresponding to the intake and exhaust ports of the head. Then, the mold is filled with molten metal to form the head with the port liners being integrally cast therewith.

Method for forming a fiber reinforced ceramic matrix composite

An internal combustion engine of either two-cycle or four-cycle construction including a block having at least one cylinder bore therein having sidewalls carrying a liner of a structural fiber reinforced ceramic matrix composite material disposed in sealed fiber reinforced sliding relationship within the cylinder bore, and a cylinder head sealing atop end of the cylinder bore to form a closed combustion chamber in combination with the piston. The cylinder head also has the structural fiber reinforced ceramic matrix composite material disposed on an inner surface thereof facing the combustion chamber. The preferred engine is a two-cycle engine having an externally scavenged intake system and an oil sump lubricating system thereby eliminating the need to separately mix or inject lubricating oil. Higher operating temperatures and closer tolerances allow higher fuel efficiency and less pollutant production. A preferred structural fiber reinforced ceramic matrix composite material and the method of making same is also disclosed.

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Riverside, CA, United States of America

Steven Donald Atmur