Abstract: 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.

Abstract: An aluminum-nitrogen polymer is prepared by reacting an organic nitrile with a dialkylaluminum hydride to form an organoaluminum imine, and heating the imine to a temperature of 50.degree. to 200.degree. C. for at least 2 hours. The polymeric product can be subjected to an additional heat treatment to form a more highly cross-linked polymer. After either heat treatment the polymeric product can be further reacted with a primary amine or ammonia. The organoaluminum imine as well as the aminated or non-aminated polymers can be pyrolyzed to form an aluminum nitride-containing ceramic.

Abstract: The present invention is directed to compositions derived from polymers containing metal-nitrogen bonds, which compositions exhibit, among other things, desirable oxidation resistance, corrosion resistance and hydrolytic stability when exposed to adverse environments, whether at ambient or at elevated temperatures, and which may be useful as, for example, protective coatings on surfaces.

Abstract: The present invention relates to the use of a gating means in combination with a spontaneous infiltration process to produce a metal matrix composite body. Particularly, a permeable mass of filler material or a preform is spontaneously infiltrated by molten matrix metal to form a metal matrix composite body. A gating means is provided which controls or limits the areal contact between molten matrix metal and the filler material or preform. The use of a gating means provides for control of the amount of matrix metal which can contact the preform or filler material, which may result in less machining of a formed metal matrix composite body compared with a similar metal matrix composite body made without a gating mean. Moreover, the use of a gating means ameliorates the tendency of a formed metal matrix composite body to warp due to the contact between the formed composite body and matrix metal carcass.

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 method for forming metal matrix composite bodies. Particularly, a permeable mass of filler material is formed into a preform. 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 the molten matrix metal. A means for maintaining the preform at least partially below the surface of the molten matrix metal can also be utilized.

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 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.

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 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 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 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.