Method of making a diamond-coated composite body
AssigneeSt. Gobain/Norton Industrial Ceramics Corp.
InventorJames M. Olson
Life of this patent
Estimating the term…
Abstract
At least the surface region of a cutting tool substrate made of tungsten carbide in a cobalt matrix is carburized to chemically passivate the cobalt prior to deposition of diamond film on it. The passivation improves adhesion by preventing reaction of the cobalt with the diamond in the course of the deposition process. To further improve adhesion of the diamond, cobalt is removed from the exposed surfaces of the tungsten carbide grains by heat treatment in inert gas or by hydrogen plasma.
Claims18
A method of preparing the surface of a composite body which comprises particulates embedded in a binder material comprising:
- passivating the binder material in at least the surface region of the body to a degree sufficient to permit the chemical vapor deposition of a diamond film on the body without significant chemical degradation of the diamond by the binder material and
- removing the binder material from the surface of exposed particulates by gas-assisted vaporization, leaving the passivated binder material at the surface between the exposed particulates.
Dependencies are inferred from the claim text.