Method for obtaining thick, adherent diamond coatings

Abstract

Abstract A method for coating a substrate with a layer of chemical vapor deposition (CVD) diamond comprises attaching a screen to the area of the substrate to be coated and coating said screened area with a layer of CVD diamond. Preferably, the screen is attached only at its edges by spot welding or arc welding the screen to the area of the surface where the diamond coating is desired. The screen serves two functions : it creates a more favorable surface for diamond deposition; and it provides a semi-flexible surface that aids to relax stresses that occur in the diamond film both during growth and during cool down to room temperature. The screen may be made from carbide-forming materials, such as Mo or W, to create a surface that is more favorable for diamond growth. Upon cooling, the fine screen distorts to relieve the compressive stresses that occur in the film due to diamond's low coefficient of thermal expansion. Although the diamond may not be in direct physical contact with the underlying substrate, a good physical bond is provided by the welding process, thereby allowing the diamond film to remain intact and serve as a protective coating.

Inventors

• 👤 Randall J. Kehl

Bibliographic Details