Abstract:
This invention relates generally to a novel method for removing metal from a formed self-supporting body. A self-supporting body is made 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 donor material (e.g., boron nitride) and, optionally, one or more inert fillers. Once the self-supporting body is formed, it is then subjected to appropriate conditions which causes metallic constituent contained in the self-supporting body to be at least partially removed.
Abstract:
This invention relates generally to novel methods of preparing self-supporting bodies and to the novel products made thereby. In its more specific aspects, this invention relates to methods of producing self-supporting bodies having controlled porosity and graded properties and comprising one or more boron-containing compounds, e.g., a boride or a boride and a carbide. The method comprises, in one embodiment, reacting a powdered parent metal, in molten form, with a bed or mass comprising a boron donor material and a carbon donor material (e.g., boron carbide) and, optionally, one or more inert fillers, to form the body. In another embodiment, both of a powdered parent metal and a body or pool of molten parent metal are induced to react with a bed or mass comprising a boron donor material and a carbon donor material (e.g., boron carbide) and, optionally, one or more inert fillers to produce a grading effect in the resultant body. In addition, combustible additives (e.g., gelatin, corn starch, wax, etc.) can be mixed with the bed or mass comprising, for example, a boron carbide material to aid in porosity production and control. When the self-supporting body of the instant invention is formed while in contact with a previously formed ceramic, metal or composite body, a bond can be formed between the two bodies, thus creating a macrocomposite body.
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 and/or an infiltration enhancer precursor and/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.
Abstract:
This invention relates to a novel method for producing self-supporting composite bodies, formed by the oxidation reaction of a parent metal and a solid-phase oxidant to produce at least one oxidation reaction product comprising, in most cases, at least one intermetallic phase, and, optionally, having at least one metallic component introduced during formation of the body to impart certain properties to the formed body. The invention also relates to formation of, in some cases, ceramic phases in addition to the intermetallic phase(s).
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 fiber reinforced ceramic matrix composite body. Particularly, by providing at least one of an infiltration enhancer and/or an infiltration enhancer precursor and/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.
Abstract:
There is disclosed a method for producing a self-supporting ceramic body by oxidation of a molten precursor metal with a vapor-phase oxidant to form an oxidation reaction product and inducing a molten flux comprising said molten precursor metal through said oxidation reaction product. A second metal is incorporated into said molten flux during the oxidation reaction. The resulting ceramic body includes sufficient second metal such that one or more properties of said ceramic body are at least partially affected by the presence and properties of said second metal in the metallic constituent.