EP0261053A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Production of ceramic and ceramic-metal composite articles with surface coatings
Assignee: Lanxide Technology Co LP
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Filing: 1987-09-01
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Granted: —
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Expires: 2007-09-01
Abstract
Abstract The invention comprises a method of making self-supporting composite ceramic 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 body. The composite is recovered and in a separate subsequent operation, the 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.
Inventors
- 👤 Marc S. Newkirk
- 👤 Adam J. Gesing
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 14:20
CPC Classifications
C; C04; C04B; C04B35/00; C04B41/00; C04B41/009; C04B35/622; C04B35/64; C04B35/65; C04B35/652; C04B41/45; C04B41/50; C04B41/5053; C04B41/51; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C04B41/88; C22; C22C; C22C1/00; C22C1/10; C22C1/1036; C22C1/1057; C22C1/1063; C22C29/00; C22C29/12; F; F41; F41H; F41H5/00; F41H5/02; F41H5/04; F41H5/0414
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
214 words
A method for producing a self-supporting ceramic body by oxidation of a parent meal to form a polycrystalline material consisting essentially of (1) the oxidation reaction product of said parent metal with a vapor-phase oxidant, and, optionally, (2) one or more non-oxidized constituents of the parent metal, the method comprising: heating said parent metal to a temperature above the melting point of said parent metal but below the melting point of the oxidation reaction product to form a body of molten metal and, at said temperature: (a) reacting said body of molten metal with said vapor-phase oxidant to form said oxidation reaction product, optionally with one or more dopant(s) added, (b) maintaining at least a portion of said oxidation reaction product in contact with an between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards the oxidant so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product, and, optionally, leaving non-oxidized constituents of said parent metal dispersed through said polycrystalline material, and recovering said ceramic body, and (c) coating the surface of said recovered body with one or more materials which effects desired changes to the properties of said surface, and recovering said ceramic body.
Claim 2
Independent Claim
214 words
A method for producing a self-supporting ceramic body by oxidation of a parent meal to form a polycrystalline material consisting essentially of (1) the oxidation reaction product of said parent metal with a vapor-phase oxidant, and, optionally, (2) one or more non-oxidized constituents of the parent metal, the method comprising: heating said parent metal to a temperature above the melting point of said parent metal but below the melting point of the oxidation reaction product to form a body of molten metal and, at said temperature: (a) reacting said body of molten metal with said vapor-phase oxidant to form said oxidation reaction product, optionally with one or more dopant(s) added, (b) maintaining at least a portion of said oxidation reaction product in contact with an between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards the oxidant so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product, and, optionally, leaving non-oxidized constituents of said parent metal dispersed through said polycrystalline material, and recovering said ceramic body, and (c) coating the surface of said recovered body with one or more materials which effects desired changes to the properties of said surface, and recovering said ceramic body.
Claim 3
Independent Claim
296 words
A method for producing a self-supporting ceramic composite structure adapted or fabricated for use as an article of commerce comprising (1) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material consisting essentially of (i) the oxidation reaction product of said parent metal with a vapor-phase oxidant and, optionally, (ii) one or more non-oxidized constituents of the parent metal; and (2) one or more fillers embedded by said matrix, the method comprising the steps of: (a) positioning said parent metal adjacent to a permeable mass of filler and orienting said parent metal and said filler relative to each other so that formation of said oxidation reaction product will occur in a direction towards and into said mass of filler; (b) heating said parent metal to a temperature above its melting point but below the melting point of said oxidation reaction product to form a body of molten parent metal and reacting the molten parent metal with said oxidant at said temperature to form said oxidation reaction product, and at said temperature maintaining at least a portion of said oxidation reaction product in contact with and extending between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards and into the adjacent mass of filler so that oxidation reaction product continues to form within the mass of filler at the interface between the oxidant and previously formed oxidation reaction product, and continuing said reacting for a time sufficient to embed at least a portion of the filler within said polycrystalline material, and recovering the ceramic composite; and (c) coating the surface of said recovered composite with one or more materials which effect desired changes to the properties of said surface, and recovering said composite.
Claim 4
Independent Claim
296 words
A method for producing a self-supporting ceramic composite structure adapted or fabricated for use as an article of commerce comprising (1) a ceramic matrix obtained by oxidation of a parent metal to form a polycrystalline material consisting essentially of (i) the oxidation reaction product of said parent metal with a vapor-phase oxidant and, optionally, (ii) one or more non-oxidized constituents of the parent metal; and (2) one or more fillers embedded by said matrix, the method comprising the steps of: (a) positioning said parent metal adjacent to a permeable mass of filler and orienting said parent metal and said filler relative to each other so that formation of said oxidation reaction product will occur in a direction towards and into said mass of filler; (b) heating said parent metal to a temperature above its melting point but below the melting point of said oxidation reaction product to form a body of molten parent metal and reacting the molten parent metal with said oxidant at said temperature to form said oxidation reaction product, and at said temperature maintaining at least a portion of said oxidation reaction product in contact with and extending between said body of molten metal and said oxidant, to draw molten metal through the oxidation reaction product towards and into the adjacent mass of filler so that oxidation reaction product continues to form within the mass of filler at the interface between the oxidant and previously formed oxidation reaction product, and continuing said reacting for a time sufficient to embed at least a portion of the filler within said polycrystalline material, and recovering the ceramic composite; and (c) coating the surface of said recovered composite with one or more materials which effect desired changes to the properties of said surface, and recovering said composite.
Claim 5
Dependent Claim
45 words
The process of Claim 1 or Claim 2 wherein said coating is selected from the group consisting of one or more of the elements aluminum, boron, carbon, cobalt, copper, chromium, germanium, hafnium, molybdenum, nickel, niobium, palladium, platinum, silicon, silver, tin, tantalum, vanadium, tungsten, and zirconium.
Claim 6
Dependent Claim
28 words
The process of Claim 3 wherein said coating comprising one or more of said elements is applied to said surface by a chemical or physical vapor deposition process.
Claim 7
Dependent Claim
32 words
The process of Claim 1 or Claim 2 wherein said coating comprises one or more carbides, nitrides, or oxides of aluminum, boron, chromium, hafnium, molybdenum, niobium, tantalum, titanium, vanadium, tungsten, and zirconium.
Claim 8
Dependent Claim
177 words
In a method for producing a self-supporting ceramic body by steps including the oxidation of a molten parent metal with an oxidant to form an oxidation reaction product, and continuing said oxidation reaction for a time sufficient to produce said ceramic body comprising said oxidation reaction product and an interconnected, metal-containing component, which component is at least partially interconnected and at least partially accessible from an external surface of the ceramic body, the improvement comprising: (a) contacting said external surface of said cermaic body with a foreign metal different from said parent metal, so as to create a concentration gradient between said two metals; (b) allowing sufficient time for interdiffusion of said two metals whereby a portion of said interconnected, metal-containing component is at least partially displaced in said ceramic body by said foreign metal; (c) recovering said ceramic body; (d) selectively coating the surface of said foreign metal component in said recovered body with one or more elements to effect desired changes to the properties of said surface; and (e) recovering the resulting coated ceramic body.
Claim 9
Dependent Claim
177 words
In a method for producing a self-supporting ceramic body by steps including the oxidation of a molten parent metal with an oxidant to form an oxidation reaction product, and continuing said oxidation reaction for a time sufficient to produce said ceramic body comprising said oxidation reaction product and an interconnected, metal-containing component, which component is at least partially interconnected and at least partially accessible from an external surface of the ceramic body, the improvement comprising: (a) contacting said external surface of said cermaic body with a foreign metal different from said parent metal, so as to create a concentration gradient between said two metals; (b) allowing sufficient time for interdiffusion of said two metals whereby a portion of said interconnected, metal-containing component is at least partially displaced in said ceramic body by said foreign metal; (c) recovering said ceramic body; (d) selectively coating the surface of said foreign metal component in said recovered body with one or more elements to effect desired changes to the properties of said surface; and (e) recovering the resulting coated ceramic body.
Claim 10
Dependent Claim
37 words
A process according to Claim 6 or Claim 13 wherein said foreigh metal is selected from the group consisting of one or more of chromium, iron, manganese, molybdenum, nickel, niobium, silicon, titanium, tungsten, vanadium, and alloys thereof.
Claim 11
Dependent Claim
46 words
A process according to Claim 6 or Claim 13 wherein said elements are selected from the group consisting of one or more of aluminum, boron, carbon, chromium, cobalt, copper, germanium, hafnium, molybdenum, nitrogen, nickel, niobium, palladium, platinum, silicon, silver, tin, tantalum, titanium, tungsten, vanadium and zirconium.
Claim 12
Dependent Claim
52 words
A process according to Claim 6 or Claim 13 wherein said foreign metal comprises iron, said one or more elements is carbon, and said coating is applied in step (c) by heating said composite in an atmosphere comprising a hydrocarbon gas for a period of 5-30 hours at a temperature of 800-1000°C.
Claim 13
Dependent Claim
51 words
A process according to Claim 6 or Claim 13 wherein said foreign metal comprises iron, said one or more elements is nitrogen, and said coating is applied in step (c) by heating said composite in an atmosphere comprising anhydrous ammonia for a period of 5-80 hours at a temperature of 500-600°C.
Claim 14
Dependent Claim
62 words
A process according to Claim 6 or Claim 13 wherein said foreign metal comprises iron, said elements comprise both carbon and nitrogen, and said coating is applied in step (c) by heating said composite in an atmosphere comprising a hydrocarbon gas admixed with a minor proportion of anhydrous ammonia, for a period of 1 to 5 hours at a temperature of 800-1000°C.
Claim 15
Dependent Claim
33 words
A process according to Claim 6 or Claim 13 wherein said coating comprises one or more borides, nitrides, or oxides of aluminum, boron, chromium, hafnium, molybdenum, niobium, tantalum, titanium, vanadium, tungsten, and zirconium.
Claim 16
Independent Claim
275 words
A method for producing a self-supporting ceramic body by oxidation of a parent metal, which comprises: (a) heating said parent metal to a temperature above its melting point, but below the melting point of an oxidation reaction product obtained as defined below, to form a body of molten parent metal, reacting said molten parent metal with a vapor-phase oxidant at such temperature to form said oxidation reaction product, and maintaining said oxidation reaction product in contact with and extending between said body of molten metal and said oxidant; (b) maintaining the temperature so as to keep the metal molten, and progressively drawing molten metal through the oxidation reaction product so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product; and (c) continuing said reaction for a time sufficient to produce said ceramic body comprising said oxidation reaction product and an interconnected, metal-containing component, which component is at least partially interconnected and at least partially accessible from an external surface of the ceramic body; (d) contacting said external surface of said ceramic body with a foreigh metal different from said parent metal, so as to create a concentration gradient between said two metals; (e) allowing sufficient time for interdiffusion of said two metals whereby a portion of said interconnected, metal-containing component is at least partially displaced in said ceramic body by said foreign metal; (f) recovering said ceramic body; (g) selectively coating the surface of said foreign metal component in said ceramic body with one or more elements to effect desired changes to the properties of said surface; and (h) recovering the resulting coated ceramic body.
Claim 17
Independent Claim
275 words
A method for producing a self-supporting ceramic body by oxidation of a parent metal, which comprises: (a) heating said parent metal to a temperature above its melting point, but below the melting point of an oxidation reaction product obtained as defined below, to form a body of molten parent metal, reacting said molten parent metal with a vapor-phase oxidant at such temperature to form said oxidation reaction product, and maintaining said oxidation reaction product in contact with and extending between said body of molten metal and said oxidant; (b) maintaining the temperature so as to keep the metal molten, and progressively drawing molten metal through the oxidation reaction product so that oxidation reaction product continues to form at the interface between the oxidant and previously formed oxidation reaction product; and (c) continuing said reaction for a time sufficient to produce said ceramic body comprising said oxidation reaction product and an interconnected, metal-containing component, which component is at least partially interconnected and at least partially accessible from an external surface of the ceramic body; (d) contacting said external surface of said ceramic body with a foreigh metal different from said parent metal, so as to create a concentration gradient between said two metals; (e) allowing sufficient time for interdiffusion of said two metals whereby a portion of said interconnected, metal-containing component is at least partially displaced in said ceramic body by said foreign metal; (f) recovering said ceramic body; (g) selectively coating the surface of said foreign metal component in said ceramic body with one or more elements to effect desired changes to the properties of said surface; and (h) recovering the resulting coated ceramic body.
References Cited (Backward Citations)
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