Method of polishing diamond films
AssigneeAurburn University
InventorYonhua Tzeng
Life of this patent
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Abstract
An improved process for smoothing the surface of a diamond or diamond film comprises placing the surface of the diamond against the surface of a metal plate and heating the diamond and the plate to a temperature greater than the melting point of metal carbide and less than the melting point of the metal itself. The carbon atoms in the diamond diffuse or dissolve through solid state diffusion into the metal to form metal carbide. The metal carbide melts and around the points of contact between the diamond and the metal surface, which accelerates the diffusion or dissolution of the diamond and thereby accelerates the smoothing of the diamond surface. When the surface of the diamond is smoothed, it is cooled, removed from the plate, and cleaned of residual metal carbide.
Claims23
A method of polishing a surface of a diamond, comprising the steps of:
- placing the surface of the diamond on a surface of a metal selected from the group consisting of iron and steel, with peaks in the surface of the diamond forming points of contact between the diamond and metal surface;
- heating the metal surface to a predetermined temperature above a melting temperature of a metal carbide formed by diffusion of carbon from the diamond to the metal surface at the points of contact and below the melting temperature of the metal surface to form a liquid metal carbide film at the points of contact between the diamond surface and the metal surface;
- and
- maintaining the surface of the diamond in contact with the liquid metal carbide film formed between the diamond surface and the heated metal surface for a predetermined time sufficient for selected peaks to be eroded away through diffusion of the diamond with the liquid metal carbide film at the points of contact to form a smooth polished surface on the diamond without applying substantial additional pressure to the diamond against the metal sufficient to cause the liquid metal carbide film at the points of contact to be urged away from the points of contact.
A method of smoothing a surface of a diamond comprising the steps of;
- (a) placing the surface of the diamond in contact with a polished metal surface having a smoothness corresponding to the desired smoothness of the diamond surface, and heating the diamond and metal surface to form liquid metal carbide through diffusion of carbon atoms between the diamond and the metal surface at points of contact between the diamond and the metal surface;
- (b) heating the metal surface to a temperature greater than the melting point of the metal carbide to continue forming liquid metal carbide at the points of contact between the diamond and the metal surface, the liquid metal carbide for accelerating the diffusion of carbon atoms from the diamond into the metal surface at the points of contact;
- and
- (c) maintaining the surface of the diamond in contact with the liquid metal carbide formed between the surface of the diamond and the metal surface without requiring application of substantial additional pressure to the diamond sufficient to cause the liquid metal carbide to be urged away from the points of contact between the diamond and the metal surface, and dissolving peaks formed in the diamond surface, which form the points of contact with the liquid metal carbide, until the surface of the diamond is smoothed to a desired smoothness.
In a process of smoothing the surface of a diamond wherein the diamond surface is placed in contact with a metal surface and wherein the diamond surface is smoothed through the diffusion of carbon atoms from the diamond surface into which liquid metal carbide is formed at points of contact between the diamond surface and the metal surface, the improvement comprising:
- (a) heating the metal surface to a temperature greater than the melting point of the metal carbide to form the liquid metal carbide at points of contact between the diamond surface and the metal surface;
- (b) maintaining the diamond surface in contact with the metal surface without application of substantial additional pressures sufficient to urge the liquid metal carbide away from the points of contact;
- and
- (c) progressively and selectively dissolving the carbon atoms into the liquid metal carbide at the points of contact to smooth the diamond surface to a desired amount with minimal dissolution of the diamond surface.
A method of forming a diamond surface having a desired configuration, comprising:
- (a) placing a diamond on a metal surface having a topography to match the desired configuration of the diamond surface with portions of the surface of the diamond to be treated engaging the metal surface to form points of contact between the diamond and metal surfaces;
- (b) heating the metal surface to a temperature below a melting temperature of the metal surface to form a liquid metal carbide layer as carbon atoms from the diamond surface diffuse into the metal surface at the points of contact between the metal surface and diamond surface;
- (c) maintaining the surface of the diamond in contact with the liquid metal carbide formed at the points of contact to progressively and selectively dissolve portions of the diamond surface with the liquid metal carbide until the diamond surface is reshaped to the desired configuration that is a reverse topography of the metal surface, and without applying substantial additional pressure to the diamond sufficient to cause the liquid metal carbide formed at the points of contact to be urged away from the points of contact to minimize undesired dissolution of the diamond surface.
Dependencies are inferred from the claim text.