Nanocomposite coatings on cemented carbide
AssigneeGM Global Technology Operations LLC
InventorXingcheng Xiao
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Abstract
A method of creating adherent, fracture-toughened polycrystalline diamond coatings on carbide cutting tools or other workpiece substrates through the development of composite coatings comprising polycrystalline diamond and carbon nanotubes is described. The coating is deposited through a chemical vapor deposition process using a pre-determined hydrocarbon-hydrogen gas mixture suitable for nucleating diamond on the carbide particles and carbon nanotubes on the metallic binder. The deposited coating, which may be up to 30 micrometers in thickness, is typically characterized by a diamond or diamond-like carbon matrix in which carbon nanotubes are distributed as fiber-like filler materials.
Claims16
A method for depositing an adherent diamond-containing coating on a substrate comprising metal carbide particles in a metallic binder, the method comprising:
- contacting the substrate with a gaseous mixture comprising a hydrocarbon and hydrogen under conditions enabling simultaneous deposition of carbon nanotubes and polycrystalline diamond from the gaseous mixture onto the substrate, the deposited coating comprising a layer of polycrystalline diamond containing carbon nanotubes.
A method for depositing an adherent polycrystalline diamond-containing coating on a tool substrate comprising metal carbide particles in a metallic cobalt binder, the metallic carbide particles and cobalt both being exposed at the substrate surface;
- the method comprising:
- selecting a tool substrate composition and a combination of hydrogen and at least one hydrocarbon compound as a potential gaseous mixture for deposition of carbon on the substrate;
- predetermining hydrocarbon compound and hydrogen gaseous mixtures for the selected substrate and temperature and pressure parameters for contacting the tool substrate with the gaseous mixtures to co-deposit on the substrate surface a coating layer consisting essentially of a polycrystalline diamond matrix containing carbon nanotubes;
- and thereafter
- depositing such coating layer on the substrate using the predetermined gaseous mixtures and parameters.
An article comprising a substrate comprising metallic carbide particles in a metallic binder matrix, the substrate having a surface with a composite surface coating with a diamond matrix containing carbon nanotubes.
Dependencies are inferred from the claim text.