Abstract: A metal injection-molding feedstock is heated and plasticized. Supercritical carbon dioxide is injected into the feedstock to form micropores when the pressure is reduced and a parts mold is filled. The micropores are retained when the green parts are debindered and sintered.

Abstract: A metal injection-molding feedstock is heated and plasticized. Supercritical carbon dioxide is injected into the feedstock to form micropores when the pressure is reduced and a parts mold is filled. The micropores are retained when the green parts are debindered and sintered.

Abstract: A metal injection-molding feedstock is heated and plasticized. Supercritical carbon dioxide is injected into the feedstock to form micropores when the pressure is reduced and a parts mold is filled. The micropores are retained when the green parts are debindered and sintered.

Abstract: This invention relates to metal and ceramic matrix composite brake rotors comprising an interconnected matrix embedding at least one filler material. In the case of metal matrix composite materials, the at least one filler material comprises at least about 26% by volume of the brake rotor for most applications, and at least about 20% by volume for applications involving passenger cars and trucks. In a preferred embodiment of the present invention, the metal matrix composite brake rotor comprises an interconnected metal matrix containing at least about 28% by volume of a particulate filler material and more preferably at least about 30% by volume. Moreover, the composite rotors of the present invention exhibit a maximum operating temperature of at least about 900.degree. F. and preferably at least about 950.degree. F. and even more preferably at least about 975.degree. F. and higher.

Abstract: 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.

Abstract: This invention relates to metal and metal matrix composite materials that are useful as, for example, brake rotors, clutch plates and other similar uses which benefit from material properties of the invention. In the case of metal matrix composite materials, clutch plates and brake rotors made according to the invention comprise an interconnected matrix metal embedding at least one filler material. For example, the at least one filler material comprises numerous acceptable filler materials present in a sufficient quantity to provide desired performance. The brake rotors and clutch plates according to the invention further comprise a coating on the surface thereof causing the metal or metal matrix composite body to function as a substrate. The coatings may be applied by various conventional techniques.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies by using a barrier material. Particularly, an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere are in communication with a filler material or a preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform up to the barrier material. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum. Accordingly, shaped metal matrix composite bodies can be produced having superior surface finish.

Abstract: The present invention relates to a novel process for making a macrocomposite body. Specifically, a metal matrix composite body is first formed and thereafter, a ceramic body or a ceramic matrix composite body is caused to form from at least one surface of the already formed metal matrix composite body. The ceramic or ceramic composite body can be formed by, for example, changing from spontaneous infiltration conditions which permit a molten matrix metal to infiltrate a filler material or preform to conditions which favor the growth of a ceramic oxidation reaction product from the matrix metal (e.g., the matrix metal serves the dual role of a matrix metal and a parent metal for growth of oxidation reaction product). The growth of oxidation reaction product can occur from one or more surfaces of a metal matrix composite body and can be controlled to result in any desired shape.

Abstract: Organometallic ceramic precursor binders are used to fabricate shaped bodies by different techniques. Exemplary shape making techniques which utilize hardenable, liquid, organometallic, ceramic precursor binders include the fabrication of negatives of parts to be made (e.g., sand molds and sand cores for metalcasting, etc.), as well as utilizing ceramic precursor binders to make shapes directly (e.g., brake shoes, brake pads, clutch parts, grinding wheels, polymer concrete, refractory patches and liners, etc.). A preferred embodiment of the invention involves the fabrication of preforms used in the formation of composite articles.

Abstract: This invention relates generally to a novel method of manufacturing a composite body. More particularly, the present invention relates to a method for modifying the resultant properties of a composite body, by, for example, minimizing the amount of porosity present in the composite body. Moreover, additives, whether used alone or in combination, (1) can be admixed with the permeable mass, (2) can be mixed or alloyed with the parent metal, (3) can be placed at an interface between the parent metal and the preform or mass of filler material, (4) or any combination of the aforementioned methods, to modify properties of the resultant composite body. Particularly, additives such as VC, NbC, WC, W.sub.2 B.sub.5, TaC, ZrC, ZrB.sub.2, SiB.sub.6, SiC, MgO, Al.sub.2 O.sub.3, ZrO.sub.2, CeO.sub.2, Y.sub.2 O.sub.3, La.sub.2 O.sub.3, MgAl.sub.2 O.sub.4, HfO.sub.2, ZrSiO.sub.4, Yb.sub.2 O.sub.3 and Mo.sub.2 B.sub.

Abstract: A method is provided for producing a self-supporting ceramic composite body having a plurality of spaced apart wall members, each wall member having a bounded cross-section for defining substantially continuous, fluid passageways. The wall members generally inversely replicate in opposed directions the geometry of a positive pattern. Each of the wall members, which are axially aligned, comprises a ceramic matrix having a filler embedded therein, and is obtained by the oxidation reaction of a parent metal to form a polycrystalline material which consists essentially of the oxidation reaction product of the parent metal with an oxidant and, optionally, one or more metals, e.g. nonoxidized constituents of the parent metal.

Abstract: There is disclosed a method for making a self-supporting ceramic composite article having a porous core bearing a dense surface layer formed integrally with said core. A preform comprises a filler material and parent metal distributed therethrough, wherein the volume percent of parent metal is sufficient to form a volume of oxidation reaction product exceeding the total volume available within said preform. The parent metal is melted and reacted with an oxidant to form an oxidation reaction product filling the spatial volume and leaving voids. The reaction is continued to further transport molten parent metal through the oxidation reaction product to at least one surface of the preform to form oxidation reaction product on said surface substantially free of voids thereby forming a relatively dense surface layer.

Abstract: The present invention relates to a novel method for forming a metal matrix composite body. Particularly, a permeable mass of filler material is formed into a preform, the preform having at least a portion thereof which contains a cavity. An infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are also in communication with the preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the preform when the preform is placed into molten matrix metal. An infiltrating atmosphere is provided in communication with the cavity in the preform for at least a portion of the process, and molten matrix metal is contacted with an exterior portion of the preform, such that molten matrix metal will spontaneously infiltrate the preform from an exterior surface thereof toward the cavity. The process can be performed in a continual manner.

Abstract: A method for producing a self-supporting ceramic composite body which comprises preparing a polycrystalline material as the oxidation reaction product of a parent metal with a vapor-phase oxidant, comminuting the resulting material to a particulate, forming a permeable mass of said particulate as filler, and infiltrating said particulate with an oxidation reaction product of a parent metal with a vapor-phase oxidant, thereby forming said ceramic composite body.

Abstract: There is disclosed methods for producing self-supporting ceramic matrix and ceramic matrix composite bodies by batch, semi-continuous, and continuous processes utilizing the directed oxidation of a molten parent metal with an oxidant to form an oxidation reaction product which may embed filler material.

Abstract: A method is provided for producing a self-supporting ceramic composite body having a plurality of spaced apart wall members, each wall member having a bounded cross-section for defining substantially continuous, fluid passageways. The wall members generally inversely replicate in opposed directions the geometry of a positive pattern. Each of the wall members, which are axially aligned, comprises a ceramic matrix having a filler embedded therein, and is obtained by the oxidation reaction of a parent metal to form a polycrystalline material which consists essentially of the oxidation reaction product of the parent metal with an oxidant and, optionally, one or more metals, e.g. nonoxidized constituents of the parent metal.

Abstract: The present invention relates to a novel process for forming macrocomposite bodies. Particularly, a suitable matrix metal, typically in a molten state, is in contact with a suitable mass of filler material or preform located adjacent to, or in contact with, at least one second material in the presence of a suitable reactive atmosphere in an impermeable container, at least at some point during the process, which permits a reaction to occur between the reactive atmosphere and the molten matrix metal and/or mass of filler material or preform and/or impermeable container, thereby causing molten matrix metal to infiltrate the mass of filler material or preform due to, at least in part, the creation of a self-generated vacuum. The impermeable container being sealed by a molten glassy material. Such self-generated vacuum infiltration occurs without the application of any external pressure or vacuum.

Abstract: This invention relates to a method for producing a self-supporting ceramic structure comprising an oxidation reaction product of a parent metal and a vapor-phase oxidant characterized by an altered microstructure attributable to the addition of one or more process modifiers relative to substantially the same oxidation reaction product produced without a process modifier.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies. Particularly, a suitable matrix metal, typically in a molten state, is in contact with a suitable filler material or preform in the presence of a suitable reactive atmosphere in a sealed impermeable container, at least at some point during the process, which permits a reaction to occur between the reactive atmosphere and the molten matrix metal and/or filler material or preform and/or impermeable container, thereby causing molten matrix metal to infiltrate the filler material or preform due to, at least in part, the creation of a self-generated vacuum. Such self-generated vacuum infiltration occurs without the application of any external pressure or vacuum.

Abstract: A method of producing self-supporting ceramic a ceramic composite structures comprising (i) a polycrystalline oxidation reaction product formed upon oxidation of a body of molten parent metal with an oxidant, and (ii) interconnected porosity at least partially accessible from one or more surfaces of the ceramic body. A second polycrystalline ceramic or ceramic composite material is incorporated into the porosity of the ceramic or ceramic composite body to modify or contribute to its properties.