Composite article and method of making same

• US 4,397,901 A
• Filed: 06/15/1981
• Issued: 08/09/1983
• Est. Priority Date: 07/31/1979
• Status: Expired

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Refractory Composites Incorporated
• Inventors: Warren, James W.
• Primary Examiner(s): Thibodeau, Paul J.
• Application Number:
  US06/273,958
• Time in Patent Office: 785 Days
• Field of Search: 428/288, 428/367, 428/371, 428/391, 428/408, 428/280, 428/289, 428/245, 428/101, 427/227, 427/228, 427/249, 427/255.4, 427/255.5, 427/299, 427/333, 427/419.7, 427/431, 264/83, 264/232, 264/257, 423/447.3, 423/450
• US Class Current: 428/101
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C04B 30/02 containing fibrous materials
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 35/573 obtained by reaction sintering or recrystallisation
• CPC Class Codes: C04B 35/80 Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4529 applied from the gas phase
• CPC Class Codes: C04B 41/455 the coating or impregnating process including a chemical conversion or reaction
• CPC Class Codes: C04B 41/4584 Coating or impregnating of particulate or fibrous ceramic material C04B20/10, C04B35/628 take precedence
• CPC Class Codes: C04B 41/5001 with carbon or carbonisable materials
• CPC Class Codes: C04B 41/5053 non-oxide ceramics carbon or carbonisable materials C04B41/5001
• CPC Class Codes: C04B 41/5059 Silicon carbide
• CPC Class Codes: C04B 41/52 Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/89 for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: D01F 11/123 Oxides
• CPC Class Codes: D01F 11/124 Boron, borides, boron nitrides
• CPC Class Codes: D01F 11/125 Carbon
• CPC Class Codes: D01F 11/128 Nitrides, nitrogen carbides nitrogen borides D01F11/124
• CPC Class Codes: D01F 9/127 by thermal decomposition of hydrocarbon gases or vapours or other carbon-containing compounds in the form of gas or vapour, e.g. carbon monoxide, alcohols
• CPC Class Codes: Y10T 428/24025 Superposed movable attached layers or components
• CPC Class Codes: Y10T 428/2918 : including free carbon or carbide or therewith [not as steel]
• CPC Class Codes: Y10T 428/2933 : Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2962 : Silane, silicone or siloxane in coating
• CPC Class Codes: Y10T 428/30 : Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 442/2098 : At least two coatings or impregnations of different chemical composition

Abstract

A method of making a composite article and a composite article specifically adapted for use in high temperature, corrosive and errosive environments comprising a carbon fibrous substrate, including a pyrolytic carbon sheath formed about each fiber of the substrate; a metallic carbide, oxide, or nitride compliant coating over the coated fibers of the substrate; and an impermeable metallic carbide, oxide or nitride outer protective layer formed about the entire periphery of the coated substrate. In accordance with the method of the invention, the compliant metallic coating is applied to the fibers in a manner such that any mechanical stresses built-up in the substrate due to a mismatch between the coefficient of thermal expansion of the fibrous substrate and the coating are effectively accomodated.

Claims

1. A carbon-silicon composite anisotropic article comprising a multiplicity of carbon fibers forming a shaped article, a coating of pyrolytic carbon extending over each of said fibers, a reaction formed diffusion coating of silicon extending substantially over each of said pyrolytic carbon coated fibers and substantially over the outer periphery of the article, said pyrolytic carbon coating and said silicon coating having been applied to said fibers in a manner whereby said fibers are free to move relative to said coatings, said carbon fibers and said silicon coating having a different coefficient of thermal expansion.

2. A carbon-silicon composite article as defined in claim 1 in which said reaction formed diffusion coating consists of silicon carbide.

3. A carbon-silicon composite article as defined in claim 1 in which said reaction formed diffusion coating consists of silicon nitride.

4. A carbon-silicon composite article as defined in claim 1 in which said reaction formed diffusion coating consists of silicon oxide.

5. A carbon-silicon composite article as defined in claim 1 in which a coating of chemical vapor deposited silicon carbide extends substantially over each of said coated fibers and substantially over the outer periphery of said article.

6. A carbon-silicon composite article as defined in claim 1 wherein the density of said article is between 0.3 gm/cc and 3.0 gm/cc.

7. A carbon-silicon composite article as defined in claim 1 wherein said multiplicity of carbon fibers forming the shaped article are in the form of a woven material having a multiplicity of interwoven carbon fibers.

8. A carbon-silicon composite article as defined in claim 1 wherein said multiplicity of carbon fibers forming the shaped article are in the form of a felt material having a multiplicity of randomly oriented fibers.

9. A carbon-silicon composite article as defined in claim 1 wherein said multiplicity of carbon fibers forming the shaped article are in the form of a macerated material having a multiplicity of randomly oriented fibers.

10. A carbon-silicon composite article as defined in claim 1 in which said carbon fibers forming said shaped article are pyrolyzed rayon.

11. A carbon-silicon composite article as defined in claim 1 in which said carbon fibers forming said shaped article are pyrolyzed polyacrylonitrile.

12. A carbon-silicon composite article as defined in claim 1 in which said carbon fibers forming said shaped article are wool.

13. A carbon-silicon composite article as defined in claim 1 in which said carbon fibers forming said shaped article are pitch fibers.