Abstract: There is provided a method for producing a self-supporting ceramic composite comprising (1) a ceramic matrix obtained by oxidation of an aluminum zinc alloy to form a polycrystalline oxidation reaction product of the metal with an oxidant, and (2) one or more fillers embedded by the matrix. The metal alloy and permeable mass of filler having at least one defined surface boundary are oriented relative to each other so that formation of the oxidation reaction product will occur into said mass of filler and in a direction towards said defined surface boundary. On heating the metal to a first temperature above its melting point but below the melting point of said oxidation reaction product to form a body of molten parent metal, the molten metal reacts with said oxidant to form said oxidation reaction product which infiltrates said mass of filler to said defined surface boundary.

Abstract: The present invention relates to a method of armoring a vehicle with a novel armor material. Particularly, a metal matrix composite body is formed with a filler material and an aluminum matrix metal, wherein the filler material comprises magnesia or titanium diboride and is present in an amount of at least 40 percent by volume. The metal matrix composite body is then placed on a portion of a vehicle.

Abstract: A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum and optionally, containing therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable vapor-phase oxidant. Within a certain temperature region and optionally, aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.

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. 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 invention concerns self-supporting ceramic structures, including ceramic composite structures embedding a filler, and methods of making them. The ceramic structures comprise a polycrystalline material made by oxidation of a body of molten parent metal with an oxidant. The polycrystalline material has a first region substrate surmounted by a terminal region stratum which is integral with the first region. The terminal region stratum which is harder and of denser, finer crystalline structure than the first region substrate and is formed in a reaction stage subsequent to the reaction stage in which the first region of polycrystalline material is formed. Growth of the first stage is attained by by attenuating or interrupting the transport of molten parent metal to the first region under conditions which nonetheless leave or maintain therein enough oxidizable molten parent metal to form the polycrystalline material of the terminal region.

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 for manufacture of Group IVB metal carbide comprising a carbide of a metal selected from the group consisting of titanium, hafnium and zirconium ceramic composites is provided wherein a permeable mass of filler and carbon is contacted with a molten Group IVB metal. The molten metal is maintained in contact with the permeable mass for a sufficient period to infiltrate the permeable mass and to react the molten metal with the carbon source to form a Group IVB metal carbide composite. The permeable mass may comprise a Group IVB metal carbide, or other inert filler, or a combination of filler materials.

Abstract: This invention relates generally to a novel method for joining at least one first self-supporting body to at least one second self-supporting body which is similar in composition to or different in composition from said at least one first self-supporting body and to novel products which result from such joining. In some of its more specific aspects, this invention relates to different techniques for joining ceramic matrix composite bodies to other ceramic matrix composite bodies of similar characteristics and for joining ceramic matrix composite bodies to bodies which have different characteristics (e.g., metals). The ceramic matrix composite bodies of this invention are produced by a reactive infiltration of a molten parent metal into a bed or mass containing at least one of a boron source material, a carbon source material, and a nitrogen source material and, optionally, one or more inert fillers.

Abstract: A ceramic-reinforced aluminum matrix composite is formed by contacting a molten aluminum-magnesium alloy with a permeable mass of ceramic material in the presence of a gas comprising from about 10 to 100% nitrogen, by volume, balance non-oxidizing gas, e.g., hydrogen or argon. Under these conditions, the molten alloy spontaneously infiltrates the ceramic mass under normal atmospheric pressures. A solid body of the alloy can be placed adjacent a permeable bedding of ceramic material, and brought to the molten state, preferably to at least about 700.degree. C., in order to form the aluminum matrix composite by 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 and/or an aluminum nitride external surface layer.

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: 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 method for forming metal matrix composite bodies. Particularly, a permeable mass of filler material is formed into a preform. An infiltration enhancer or an infiltration enhancer precursor 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. In a preferred embodiment a reservoir may be employed to supply a second metal which has a different composition from the first source of matrix metal.

Abstract: This invention relates generally to a novel method of preparing self-supporting bodies, and novel products made thereby. In its more specific aspects, this invention relates to a method for producing self-supporting bodies comprising one or more boron-containing compounds (e.g., a boride or a boride and a carbide, etc.) by reactive infiltration of molten parent metal into a preform comprising boron carbide or a boron donor material combined with a carbon donor material and, optionally, one or more inert fillers, to form the body. Specifically, a boron carbide material or combination of a boron donor material and a carbon donor material, and in either case, optionally, one or more inert fillers, are sedimentation cast, spray coated, tapped, slip cast, pressed, etc., onto or into a body and into a particular desired shape.

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.

Abstract: The present invention relates to a novel process for forming internal shapes in metal matrix composite bodies. Particularly, 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, which permits molten matrix metal to spontaneously infiltrate the filler material or preform. Additionally, the filler material or preform may contain a mandrel which is capable of surviving the infiltration process, said mandrel being removed after infiltration has occurred. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.

Abstract: A method of producing self-supporting ceramic composite bodies of desired shape by infiltrating a permeable self-support preform with polycrystalline matrix material comprising an oxidation reaction product obtained by oxidation of a parent metal precursor, such as aluminum, and optionally containing therein metallic constituents. The composite body is formed by contacting a zone of a permeable self-supporting preform, having at least one defined surface boundary spaced from said contacting zone, with a body of molten metal which is reacted with a suitable vapor-phase oxidant to form an oxidation reaction product.

Abstract: The present invention relates to self-supporting ceramics or ceramic composite bodies which include a polycrystalline ceramic material comprising the oxidation reaction product of a silicon parent metal with a nitrogenous oxidant, including a nitrogenous vapor-phase oxidant, and optionally, one or more metallic constituents dispersed throughout the polycrystalline ceramic material. A barrier means comprising, for example, at least one of titanium nitride, zirconium nitride, aluminum nitride and boron nitride or a barrier means that has undergone chemical changes or alterations may be removably attached to the self-supporting ceramics or ceramic composite bodies of the present invention.

Abstract: The present invention relates to a novel process for forming metal matrix composite bodies. Specifically, in a particularly preferred embodiment for making metal matrix composite bodies by a spontaneous infiltration technique, an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere are in communication with a rigidized filler material or a rigidized preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the rigidized filler material or riigidized preform. A structural refractory material which holds the preform is made by forming a first precursor to the supportive structural refractory material and subsequently causing the precursor to become a rigid supportive structural member. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.

Abstract: The present invention relates to a novel process for removal of at least a portion of at least one metallic component of a metallic constituent from a multi-phase composite body. Particularly, by providing at least one of an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere to be in communication with a permeable mass, which contacts at least a portion of a composite body, said metallic component of the composite body, when made molten, is caused to spontaneously infiltrate the permeable mass. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum. The metallic constituent is essentially leached or removed from the multi-phase body by spontaneous infiltration.

Abstract: Self-supporting ceramic bodies comprising a polycrystalline material comprising the oxidation reaction product of a parent metal and having therein one or more channels which inversely replicate the geometry of the configured fugitive metal are formed. These self-supporting bodies may be utilized as articles for regulating and facilitating the passage of a fluid therethrough.