Patent ID: 8383200

Claim:
A method for depositing an adherent diamond-containing coating on a surface of a substrate comprising metal carbide particles in a metallic binder, the method comprising: contacting the substrate with a gaseous mixture comprising predetermined amounts of a gaseous refractory metal halide, a gaseous hydrocarbon, and hydrogen to deposit a base layer consisting essentially of a refractory metal carbide on the substrate, the base layer covering the metal carbide particles and the metallic binder exposed at the surface of the substrate; and, thereafter progressively reducing the concentration of the gaseous refractory metal halide and hydrogen in the gaseous mixture to deposit an adherent composite coating having a refractory metal carbide phase and a polycrystalline diamond phase onto the substrate overlying the base layer, the polycrystalline diamond phase being co-deposited with and distributed in the refractory metal carbide phase.