Abstract: The present invention relates to the formation of bodies having graded properties. Particularly, the invention provides a method for forming a metal matrix composite body having graded properties. The graded properties are achieved by, for example, locating differing amounts of filler material in different portions of a formed body and/or locating different compositions of filler material in different portions of a formed body and/or locating different sizes of filler materials in different portions of a formed body. In addition, the invention provides for the formation of macrocomposite bodies wherein, for example, an excess of matrix metal can be integrally bonded or attached to a graded metal matrix composite portion of a macrocomposite body. Moreover, if desired, it is possible to produce a metal matrix composite body with substantially the same properties throughout.

Abstract: The present invention relates to a novel method for forming metal matrix composite bodies and novel metal matrix composite bodies produced thereby. Particularly, a polycrystalline oxidation reaction product of a parent metal and an oxidant is first formed. The polycrystalline oxidation reaction product is thereafter comminuted into an appropriately sized filler material which can be placed into a suitable container or formed into a preform. The filler material or preform of comminuted polycrystalline oxidation reaction product is thereafter placed into contact with a matrix metal alloy in the presence of an infiltration enhancer, and/or an infiltration enhancer precursor and/or an infiltrating atmosphere, at least at some point during the process, whereupon the matrix metal alloy spontaneously infiltrates the filler material or preform. As a result of utilizing comminuted or crushed polycrystalline oxidation reaction product, enhanced infiltration (e.g., enhanced rate or amount) is achieved.

Abstract: 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.

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 the formation of a macrocomposite body for use as an electronic package or container. The macrocomposite body is formed by spontaneously infiltrating a permeable mass of filler material or a preform with molten matrix metal and bonding the spontaneously infiltrated material to at least one second material such as a ceramic or ceramic containing body or a metal or metal containing body. Moreover, prior to infiltration, the filler material or preform is placed into contact with at least a portion of a second material such that after infiltration of the filler material or preform by molten matrix metal, the infiltrated material is bonded to said second material, thereby forming a macrocomposite body. The macrocomposite body may then be coated by techniques according to the present invention to enhance its performance or bonding capabilities.

Abstract: This invention relates to novel macrocomposite bodies. More particularly, it has been discovered that the properties of a ceramic, ceramic matrix composite or metal matrix composite body may be improved by providing on at least a portion of the surface of the body a polymer-based material which serves to protect the body from damage which might occur in the absence of the polymer-based material. One particularly preferred embodiment of the present invention is a macrocomposite shaft sleeve. Another particularly preferred embodiment is a macrocomposite apex used in a hyrocyclone separator.

Abstract: The present invention broadly relates to novel complex oxidation reaction products such as perovskite bodies, including shaped complex oxidation reaction products. This invention also includes complex oxidation reaction products which exhibit superconducting properties.

Abstract: This invention relates to a method for producing a self-supporting body comprising the steps of:(a) forming a permeable mass comprising at least one solid-phase oxidant selected from the group consisting of the halogens, sulphur and its compounds, metals, metal oxides other than the silicates, and metal nitrides other than those of boron and silicon;(b) orienting said permeable mass and a source of said parent metal relative to each other so that formation of said oxidation reaction product will occur into said permeable mass;(c) heating said source of parent metal to a temperature above the melting point of said parent metal but below the melting point of said oxidation reaction product to form a body of molten parent metal;(d) reacting said body of molten parent metal with said at least one solid-phase oxidant at said temperature to permit said oxidant at said temperature to permit said oxidation reaction product to form; and(e) maintaining at least a portion of said at least one oxidation reaction product

Abstract: The present invention relates to modifying the properties of a metal matrix composite body by a post formation process treatment and/or a substantially contiguous modification treatment. The post formation process treatment may be applicable to a variety of metal matrix composite bodies produced by various techniques, and is particularly applicable to modifying the properties of a metal matrix composite body produced by a spontaneous infiltration technique. The substantially contiguous modification process may also be used primarily in conjunction with metal matrix composite bodies produced according to a spontaneous infiltration technique. Particularly, at least a portion of the matrix metal of the metal matrix composite body and/or the filler material of the metal matrix composite body is modified or altered during and/or after the formation process.

Abstract: The invention comprises a method of making self-supporting ceramic and ceramic composite structures by the oxidation reaction of a body of molten parent metal precursor with a vapor-phase oxidant to form an oxidation reaction product. This reaction or growth is continued to form a thick, self-supporting ceramic or ceramic composite body. The body is recovered and in a separate subsequent operation, at least a portion of a surface is coated with one or more materials in order to effect desired changes in the properties of the surface, e.g., hardness, corrosion resistance.

Abstract: The present invention broadly relates to novel aluminum nitride matrix ceramic composite bodies for use as refractory materials and methods for making the same. The refractory materials are useful in environments which are corrosive, erosive, abrasive and/or which generate thermal shock. Such environments include furnaces, and associated apparatus which house or contact molten masses including, for example, molten metals, molten glasses, etc. The preferred method for making the aluminum nitride matrix ceramic composites comprises a directed oxidation of molten metal.

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: A sintered, Si.sub.3 N.sub.4 -containing ceramic article is prepared by a reaction injection molding process comprising (1) injecting into a heated mold a fluid, nondilatant mixture of (a) at least 40% by volume of a powder mixture of (i) Si.sub.3 N.sub.4, (ii) a silicate glass-forming sintering aid and (iii) a high metal content silicide, and (b) a curable Si.sub.3 N.sub.4 precursor binder, to cure the binder and produce a hardened molded article, and (2) heating the molded article under a suitable atmosphere to convert the cured binder to a Si.sub.3 N.sub.4 -containing ceramic. The molded article is then sintered under a vacuum to crystallize the silicate glass phase by deoxygenation.

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: This invention relates generally to a novel method for forming a self-supporting body. Specifically, the formed self-supporting body has a higher volume percent of metallic constituent relative to a body formed by similar techniques. A first porous self-supporting body is formed by reactively infiltrating a molten parent metal into a bed or mass containing a boron donor material and a carbon donor material (e.g., boron carbide) and/or a boron donor material and a nitrogen material (e.g., boron nitride) and, optionally, one or more inert fillers. Additionally, powdered parent metal may be admixed with a mass to be reactively infiltrated to form additional porosity therein. The porous self-supporting body which is formed by the reactive infiltration process according to this invention should contain at least some interconnected porosity which is capable of being filled in a subsequent step with additional metal, thus increasing the volume percent of parent metal in the body at the expense of porosity.

Abstract: A method of producing a self-supporting ceramic composite body having therein at least one cavity which inversely replicates the geometry of a positive mold of parent metal. The method includes embedding the mold of parent metal within a conformable bed of filler to provide therein a cavity shaped and filled by the mold. The assembly is heated to melt the parent metal mold, e.g., an aluminum parent metal mold, and contacted with an oxidant to oxidize the molten parent metal to form a polycrystalline material which grows through the surrounding bed of filler, the molten metal being drawn through the growing polycrystalline material to be oxidized at the interface between the oxidant and previously formed oxidation reaction product whereby the cavity formerly filled by the mold of parent metal is eventually evacuated of the metal. There remains behind a cavity whose shape inversely replicates the original shape of the mold.

Abstract: A ceramic forming paper sheet is prepared by dispersing in water a ceramic-forming powder, a thermoplastic pulp and wood pulp, flocculating the dispersion by adding a cationic wet strength resin and an anionic polymer, dewatering the flocculated dispersion to form a sheet, and wet pressing and drying the sheet. The sheets can be stacked, and pressed or thermoformed, followed by firing to consolidate the sheets to a ceramic.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies. Specifically, a metal which typically would not exhibit spontaneous infiltration properties under a given set of processing conditions can be induced to infiltrate a filler material or preform when combined or contacted with a matrix metal which does exhibit spontaneous infiltration properties. Stated more particularly, when an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with a filler material or a preform, at least at some point during the process, and a metal which, under the process conditions, ordinarily would not exhibit spontaneous infiltration, is combined with (e.g., alloyed, mixed with and/or exposed to) a matrix metal which does exhibit spontaneous infiltration behavior under the same processing conditions, the combination of metals will spontaneously infiltrate the filler material or preform.

Abstract: A net shaped ceramic-reinforced aluminum matrix composite is provided by forming a permeable mass of ceramic material with a defined surface boundary having a barrier, and contacting a molten aluminum-magnesium alloy with the permeable mass of ceramic material in the presence of a gas comprising from about 10 to 100% nitrogen, by volume, balance nonoxidizing gas, e.g. hydrogen or argon. Under these conditions, the molten alloy spontaneously infiltrates the ceramic mass under normal atmospheric pressures until it reaches the barrier. A solid body of the alloy can be placed adjacent to a permeable bedding of ceramic material having a barrier, and brought to the molten state, preferably to at least about 700.degree. C., in order to form the net shape aluminum matrix composite by spontaneous infiltration. In addition to magnesium, auxiliary alloying elements may be employed with aluminum. The resulting composite products may contain a discontinuous aluminum nitride phase in the aluminum matrix.