A composite material featuring nanotubes reinforcing a matrix featuring metal, glass, ceramic and/or polymer. In a preferred embodiment, the nanotubes feature elemental carbon, and the composites can be produced using a molten silicon metal infiltration technique, which may be pressurized or not, for example, a siliconizing or a reaction-bonding process. In this preferred embodiment, carbon nanotubes may be prevented from chemically reacting with the silicon infiltrant by an interfacial coating disposed between the carbon nanotubes and the infiltrant. A reaction-bonded composite body containing even a small percentage of carbon nanotubes possessed a significant increase in electrical conductivity as compared to a reaction-bonded composite not containing such nanotubes, reflecting the high electrical conductivity of the nanotubes. When the nanotubes are well dispersed throughout the preform, mechanical property enhancements start to become noticeable, such as fracture toughness enhancement. Frequently, the nanotubes as-received are tangled or agglomerated, but comminuting is an effective technique to untangle, separate or otherwise disperse the nanotubes.

Nanotube-containing composite bodies, and methods for making same

A graphite fiber reinforced metal matrix composite prepared by hot-pressing, comprising layers of a matrix metal selected from the group consisting of magnesium and magnesium based alloys; in combination with alternate layers of a graphite fiber. The improvement consists of small additions of a metal selected from the group consisting of titanium, chromium, nickel, zirconium, hafnium and silicon in order to promote wetting and bonding between the graphite fibers and the matrix metal.

Production of graphite fiber reinforced metal matrix composites

Yarns or tows of high strength composite fibers the majority of which comprise a core of carbon or the like and a thin, uniform firmly adherent electrically conductive layer or an electrodepositable metal, such as nickel or the like, the bond strength of the metal to the core being greater than 10 percent of the intermetallic bond strength of the metal layer. The composites can be produced by electrodeposition from a bath onto the core but the procedure must use external voltages high enough both (i) to dissociate the metal at the core and (ii) to nucleate the metal through the boundary layer into direct contact with the core.

Yarns and tows comprising high strength metal coated fibers, process for their production, and articles made therefrom

Copper powder, carbon fibers arranged in random directions and a metal capable of reacting with carbon fibers are homogeneously mixed together, and the mixture is heated and molded under high pressure to form an integral composite. The so formed carbon fiber-copper matrix composite has no directional characteristic in mechanical properties, and the linear thermal expansion coefficient of the composite is low and the thermal stability of the composite is so high that when it is exposed to high temperature, no damage by thermal deformation is caused.

Copper-carbon fiber composites and process for preparation thereof

The present invention relates to electrodes having fibers which provide large surface areas, high bond strength between the core fibers and metallic coatings thereon, and efficient electrical connections; electro-chemical cells including such electrodes; and processes for forming and utilizing the electrodes and cells of the invention.

Electrochemical cells and electrodes therefor

Composite articles having a nickel base metal matrix reinforced with a plurality of high strength, high modulus carbon fibers having a thin, intermediate layer of a metal carbide disposed upon at least a portion of the fiber surfaces. Such composites are characterized by improved thermal cycling characteristics and are produced by coating a plurality of carbon fibers first with a thin, continuous layer of nickel, and then with a second thin, continuous overcoating of a metal capable of diffusing through the nickel coating and reacting with carbon to form a metal carbide; and then hot pressing the dual-coated fibers for a time and at a temperature and pressure sufficient to bond them together and diffuse at least a portion of the carbide-forming metal surface layer through the nickel undercoating and effect reaction between said carbide-forming metal and said carbon fibers to produce a metal carbide coating on at least a portion of the surface of the fibers.

R Sara

Papers

Carbon fiber reinforced nickel matrix composite having an intermediate layer of metal carbide