# US 5,350,003 A · Removing metal from composite bodies and resulting products > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,003 A - Document ID: US5350003A - Status: Granted - Kind: A - Application number: 08/090,352 - Filed: 1993-07-09 - Granted: 1994-09-27 - Earliest claimed: 1993-07-09 - Assignees: Lanxide Technology Company, LP - Inventors: Birol Sonuparlak; William B. Johnson; Ali S. Fareed - Web page: https://patentgrep.com/patent/US5350003A ## CPC - C04B 41/009: {characterised by the material treated} - B22D 19/14: the objects being filamentary or particulate in form (making alloys containing fibres or filaments by contacting the fibres or filaments with molten metal C22C47/08) - C04B 41/53: involving the removal of at least part of the materials of the treated article, {e.g. etching, drying of hardened concrete (C04B41/0036 - C04B41/0054 take precedence)} - C04B 41/91: involving the removal of part of the materials of the treated articles, e.g. etching - C22C 1/1036: {starting from a melt} - C22C 1/1063: {Gas reaction, e.g. lanxide} - C22C 47/08: by contacting the fibres or filaments with molten metal, e.g. by infiltrating the fibres or filaments placed in a mould {(C22C47/16 takes precedence)} - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) - C22C: ALLOYS (treatment of alloys C21D, C22F) ## 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. ## Claims ### Claim 1 A method for removing at least one metallic component of a metallic constituent contained within a fiber reinforced ceramic matrix composite body comprising: contacting at least a portion of at least one surface of said fiber reinforced ceramic matrix composite body with at least one permeable mass comprising at least one material selected from the group consisting of at least one filler material and at least one preform of at least one filler material; and spontaneously infiltrating at least a portion of the at least one permeable mass with at least one metallic component of a metallic constituent of the fiber reinforced ceramic matrix composite body, thereby reducing the amount of said at least one metallic component in the fiber reinforced ceramic matrix composite body. ### Claim 2 (depends on 1) The method of claim 1, wherein said at least one permeable mass substantially completely surrounds said fiber reinforced ceramic matrix composite body. ### Claim 3 (depends on 1) The method of claim 1, wherein said at least one permeable mass contacts substantially only one side of said fiber reinforced ceramic matrix composite body. ### Claim 4 (depends on 1) The method of claim 1, wherein said at least one filler material comprises at least one ceramic particulate. ### Claim 5 (depends on 1) The method of claim 1, further comprising providing at least one infiltration enhancer precursor wherein said at least one infiltration enhancer is formed by reacting at least one infiltration enhancer precursor and at least one species selected from the group consisting of an infiltrating atmosphere and at least one material added to the permeable mass. ### Claim 6 (depends on 5) The method of claim 5, wherein said at least one infiltration enhancer comprises at least one nitride of magnesium formed from a reaction between a nitrogenous infiltrating atmosphere and a magnesium-containing infiltration enhancer precursor. ### Claim 7 (depends on 1) The method of claim 1, wherein said at least one permeable mass is contacted with at least one barrier means. ### Claim 8 (depends on 7) The method of claim 7, wherein said spontaneously infiltrating occurs only up to said at least one barrier means. ### Claim 9 (depends on 1) The method of claim 1, wherein said spontaneously infiltrating results in at least one gradation of at least one property in the fiber reinforced ceramic matrix composite body after at least a portion of said at least one metallic component is removed therefrom. ### Claim 10 (depends on 9) The method of claim 9, wherein said at least one gradation of at least one property occurs due to at least one step selected from the group of steps consisting of (1) discontinuing spontaneous infiltration prior to complete removal of said at least one metallic component; (2) adjusting the temperature to different set points during said spontaneous infiltration; (3) providing differing amounts of at least one infiltration enhancer or at least one infiltration enhancer precursor in at least one of said at least one permeable mass and said metallic constituent; (4) causing said at least one permeable mass which contacts said fiber reinforced ceramic matrix composite body to exhibit different properties at different portions thereof; and (5) controlling infiltration of said at least one permeable mass with the at least one metallic component from said fiber reinforced ceramic matrix composite body so as to result in differing amounts of infiltration in certain areas of the at least permeable mass relative to other areas of the at least one permeable mass. ### Claim 11 (depends on 1) The method of claim 1, wherein during or after said spontaneously infiltrating, at least one matrix conversion layer is formed in at least a portion of said fiber reinforced ceramic matrix composite body. ### Claim 12 (depends on 11) The method of claim 11, wherein said at least one matrix conversion layer is formed on at least a portion of at least one reinforcement phase in said fiber reinforced ceramic matrix composite body. ### Claim 13 (depends on 12) The method of claim 12, wherein said at least one matrix conversion layer comprises at least one reaction product formed from at least one reaction between at least a portion of said at least one metallic component and at least one other species. ### Claim 14 (depends on 13) The method of claim 13, wherein said at least one matrix conversion layer is formed from at least one reaction between at least one infiltrating atmosphere and said at least a portion of said at least one metallic component. ### Claim 15 (depends on 1) The method of claim 1, wherein said spontaneously infiltrating occurs at a temperature of at least about 650.degree. C. ### Claim 16 A method for making a ceramic matrix composite body having reduced metal content and reinforced by at least one fibrous material comprising the steps of: providing at least one fibrous material; placing at least one coating onto said at least one fibrous material; positioning at least one parent metal adjacent to said at least one fibrous material so that formation of oxidation reaction product will occur in a direction towards and into said at least one fibrous material; heating said at least one parent metal to render it molten and reacting the molten at least one parent metal with an oxidant to form at least one oxidation reaction product and causing continued oxidation reaction product to grow into the at least one fibrous material; continuing formation of oxidation reaction product for a time sufficient to embed at least a portion of the at least one fibrous material, thereby forming a fiber reinforced ceramic matrix composite body comprising a metallic constituent having at least one interconnected metallic component; contacting at least a portion of at least one surface of the formed fiber reinforced ceramic matrix composite body with at least one permeable mass comprising at least one material selected from the group consisting of at least one filler material and at least one preform of at least one filler material; and spontaneously infiltrating at least a portion of the at least one permeable mass with at least a portion of said at least one interconnected metallic component of said formed fiber reinforced ceramic matrix composite body, thereby reducing the amount of said at least one interconnected metallic component in said formed fiber reinforced ceramic matrix composite body. ### Claim 17 (depends on 16) The method of claim 16, wherein said at least one fibrous material comprises at least one material selected from the group consisting of silicon carbide-based fibers, alumina-based fibers, and carbon-based fibers. ### Claim 18 (depends on 16) The method of claim 16, wherein a chemical vapor infiltration process deposits at least two coatings on said at least one fibrous material, said at least two coatings being selected from the group of coatings consisting of boron nitrides, silicon carbides, titanium carbides, silicon nitrides, iridium, niobium and platinum. ### Claim 19 (depends on 1) The method of claim 1, further comprising providing at least one infiltration enhancer precursor, wherein at least one infiltration enhancer is formed by reacting said at least one infiltration enhancer precursor and at least one species selected from the group consisting of an infiltrating atmosphere and at least one material added to the permeable mass. ### Claim 20 (depends on 19) The method of claim 19, wherein said at least two coatings comprise a first coating of boron nitrides and a second coating of silicon carbides. ### Claim 21 A method for removing at least one metallic component of at least one metallic constituent contained within a multi-phase composite body comprising: contacting at least a portion of at least one surface of said multi-phase composite body with at least one permeable mass comprising at least one material selected from the group consisting of at least one filler material and at least one preform of at least one filler material; and spontaneously infiltrating at least a portion of the at least one permeable mass with at least a portion of the at least one metallic component of at least one metallic constituent of the multi-phase composite body, thereby reducing the amount of said at least one metallic component and said at least one metallic constituent in the multi-phase composite body. ### Claim 22 (depends on 21) The method of claim 21, wherein said at least one permeable mass substantially completely surrounds said multi-phase composite body. ### Claim 23 (depends on 21) The method of claim 21, wherein said at least one permeable mass contacts substantially only one side of said multi-phase composite body. ### Claim 24 (depends on 21) The method of claim 21, wherein said at least one filler material comprises at least one ceramic particulate. ### Claim 25 (depends on 21) The method of claim 21, wherein the at least one metallic component of the multi-phase composite body is selectively removed from only that portion of the multi-phase composite body which contacts said at least one permeable mass. ### Claim 26 (depends on 21) The method of claim 21, wherein said at least one metallic component comprises aluminum. ### Claim 27 (depends on 21) The method of claim 21, wherein said at least one permeable mass is contacted with at least one barrier means. ### Claim 28 (depends on 27) The method of claim 27, wherein said spontaneously infiltrating occurs only up to said at least one barrier means. ### Claim 29 (depends on 27) The method of claim 27, wherein said at least one barrier means is placed into contact with said at least one permeable mass by at least one process selected from the group consisting of painting, dipping, silk screening, evaporating, sputtering, depositing and contacting a solid material or sheet with said at least one permeable mass. ### Claim 30 (depends on 21) The method of claim 21, wherein said spontaneously infiltrating results in at least one gradation of at least one property in the formed multi-phase composite body after at least a portion of said at least one metallic component is removed therefrom. ### Claim 31 (depends on 30) The method of claim 30, wherein said at least one gradation of at least one property occurs due to at least one step selected from the group of steps consisting of (1) discontinuing spontaneous infiltration prior to complete removal of said at least one metallic component; (2) adjusting the temperature to different set points during said spontaneous infiltration; (3) providing differing amounts of at least one infiltration enhancer and at least one infiltration enhancer precursor in at least one of said at least one permeable mass and said at least one metallic constituent; (4) causing said at least one permeable mass which contacts said multi-phase composite body to exhibit different properties at different portions thereof; and (5) controlling infiltration of said at least one permeable mass with at least one metallic component from said multi-phase composite body so as to result in differing amounts of infiltration in certain areas of the at least one permeable mass relative to other areas of the at least one permeable mass. ### Claim 32 (depends on 21) The method of claim 21, wherein during or after said spontaneously infiltrating, at least one matrix conversion layer forms in at least a portion of said multi-phase composite body. ### Claim 33 (depends on 32) The method of claim 32, wherein said at least one matrix conversion layer forms on at least a portion of at least one reinforcement phase in said multi-phase composite body. ### Claim 34 (depends on 33) The method of claim 33, wherein said at least one matrix conversion layer comprises at least one reaction product formed from at least one reaction between at least a portion of said at least one metallic component and at least one other species. ### Claim 35 (depends on 32) The method of claim 32, wherein said at least one matrix conversion layer comprises aluminum nitride. ### Claim 36 (depends on 21) The method of claim 21, wherein said multi-phase composite body comprises a metal matrix composite body. ### Claim 37 (depends on 21) The method of claim 21, wherein said multi-phase composite body comprises a ceramic or ceramic matrix composite body. ### Claim 38 A method for removing at least one metallic component of at least one metallic constituent contained within a multi-phase composite body comprising: placing at least one composite body comprising at least two phases, one of said phases comprising a metallic component, into contact with at least one permeable mass, said at least one permeable mass comprising at least one material selected from the group consisting of at least one filler material and at least one preform comprising at least one filler material, said permeable mass contacting at least a portion of at least one surface of the at least one multi-phase composite body; communicating at least one of at least one infiltration enhancer and at least one infiltration enhancer precursor with at least one of (1) said at least one metallic component of the multi-phase composite body, (2) said at least one permeable mass, (3) said at least a portion of at least one surface and (4) at least one infiltrating atmosphere, to cause spontaneous infiltration of at least a portion of the at least one metallic component into the at least one permeable mass to occur; and spontaneously infiltrating at least a portion of the at least one permeable mass with at least one molten metallic component. ### Claim 39 (depends on 38) The method of claim 38, wherein said at least one permeable mass substantially completely surrounds said multi-phase composite body. ### Claim 40 (depends on 38) The method of claim 38, wherein said at least one permeable mass contacts substantially only one side of said multi-phase composite body. ### Claim 41 (depends on 38) The method of claim 38, wherein said at least one filler material comprises at least one ceramic particulate. ### Claim 42 (depends on 38) The method of claim 38, wherein the at least one metallic component of the multi-phase composite body is selectively removed from only that portion of the multi-phase composite body which contacts said at least one permeable mass. ### Claim 43 (depends on 38) The method of claim 38, wherein said at least one infiltrating atmosphere communicates with said at least one permeable mass for substantially all of said spontaneously infiltrating step. ### Claim 44 (depends on 38) The method of claim 38, wherein the at least one infiltration enhancer is supplied. ### Claim 45 (depends on 44) The method of claim 44, wherein the at least one infiltration enhancer is supplied to at least one of said at least one metallic component in said multi-phase composite body and said at least one permeable mass. ### Claim 46 (depends on 38) The method of claim 38, wherein said at least one metallic component comprises aluminum. ### Claim 47 (depends on 38) The method of claim 38, wherein said at least one infiltration enhancer precursor comprises magnesium. ### Claim 48 (depends on 47) The method of claim 47, wherein said at least one infiltrating atmosphere comprises nitrogen. ### Claim 49 (depends on 38) The method of claim 38, wherein said at least one infiltration enhancer is formed by reacting said at least one infiltration enhancer precursor and at least one species selected from the group consisting of the at least one infiltrating atmosphere and a material added to the at least one permeable mass. ### Claim 50 (depends on 49) The method of claim 49, wherein said at least one infiltration enhancer comprises at least one nitride of magnesium formed from a reaction between a nitrogenous infiltrating atmosphere and at least one magnesium-containing infiltration enhancer precursor. ### Claim 51 (depends on 38) The method of claim 38, wherein said at least one permeable mass is contacted with at least one barrier means. ### Claim 52 (depends on 51) The method of claim 51, wherein said spontaneously infiltrating occurs only up to said at least one barrier means. ### Claim 53 (depends on 51) The method of claim 51, wherein said at least one barrier means is placed into contact with said at least one permeable mass by at least one process selected from the group consisting of painting, dipping, silk screening, evaporating, sputtering, depositing and contacting a solid material or sheet with said at least one permeable mass. ### Claim 54 (depends on 38) The method of claim 38, wherein said spontaneously infiltrating results in at least one gradation of at least one property in the formed multi-phase composite body after at least a portion of said at least one metallic component is removed therefrom. ### Claim 55 (depends on 54) The method of claim 54, wherein said at least one gradation of at least one property occurs due to at least one step selected from the group of steps consisting of (1) discontinuing spontaneous infiltration prior to complete removal of said at least one metallic component; (2) adjusting the temperature to different set points during said spontaneous infiltration; (3) providing differing amounts of said at least one infiltration enhancer and said at least one infiltration enhancer precursor in at least one of said at least one permeable mass and said at least one metallic constituent; (4) causing said at least one permeable mass which contacts said multi-phase composite body to exhibit different properties at different portions thereof; and (5) controlling infiltration of said at least one permeable mass with at least one metallic component from said multi-phase composite body so as to result in differing amounts of infiltration in certain areas of the at least one permeable mass relative to other areas of the at least one permeable mass. ### Claim 56 (depends on 38) The method of claim 38, wherein during or after said spontaneously infiltrating, at least one matrix conversion layer forms in at least a portion of said multi-phase composite body. ### Claim 57 (depends on 56) The method of claim 56, wherein said at least one matrix conversion layer comprises aluminum nitride. ### Claim 58 (depends on 56) The method of claim 56, wherein said at least one matrix conversion layer forms on at least a portion of at least one reinforcement phase in said multi-phase composite body. ### Claim 59 (depends on 58) The method of claim 58, wherein said at least one matrix conversion layer comprises at least one reaction product formed from at least one reaction between at least a portion of said at least one metallic component and at least one other species. ### Claim 60 (depends on 58) The method of claim 58, wherein said at least one matrix conversion layer forms from at least one reaction between said at least one infiltrating atmosphere and said at least a portion of said at least one metallic component. ### Claim 61 (depends on 38) The method of claim 38, wherein said at least one metallic component comprises aluminum, said at least one infiltration enhancer precursor comprises magnesium present in an amount of at least about 0.1 percent by weight and said at least one infiltrating atmosphere comprises nitrogen. ### Claim 62 (depends on 61) The method of claim 61, wherein said spontaneously infiltrating occurs at a temperature of at least about 675.degree. C. ### Claim 63 (depends on 62) The method of claim 62, wherein said temperature is from about 675.degree. C. to about 1000.degree. C. ### Claim 64 (depends on 38) The method of claim 38, wherein said multi-phase composite body comprises a metal matrix composite body. ### Claim 65 (depends on 38) The method of claim 38, wherein said multi-phase composite body comprises a ceramic or ceramic matrix composite body.