Method for manufacturing a diamond article

• US 5,529,805 A
• Filed: 09/22/1994
• Issued: 06/25/1996
• Est. Priority Date: 09/22/1994
• Status: Expired due to Term

• Current Assignee: Diamond Innovations Incorporated (Sandvik AB)
• Original Assignee: General Electric Company
• Inventors: Iacovangelo, Charles D., Jerabek, Elihu C.
• Primary Examiner(s): BELL, JANYCE A
• Application Number:
  US08/310,449
• Time in Patent Office: 642 Days
• Field of Search: 427/226, 427/228, 427/249, 427/255.7, 427/372.2, 427/255.4, 427/399, 427/404
• US Class Current: 427/249.18
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 41/0072 Heat treatment
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4519 application under an other specific atmosphere
• CPC Class Codes: C04B 41/5057 Carbides
• CPC Class Codes: C04B 41/5133 with a composition mainly composed of one or more of the refractory metals
• CPC Class Codes: C04B 41/5144 with a composition mainly composed of one or more of the metals of the iron group
• CPC Class Codes: C04B 41/52 Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/89 for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 30/005 on hard metal substrates

Abstract

A diamond article, for example, a sheet-form diamond tool insert brazable in air. The diamond sheet has a dual layer coating, a chromium bonding layer and a protective braze compatible overcoat, such as a Ni overcoat. The interface between the Cr layer and the diamond substrate includes sufficient metal carbide component to provide adhesion. Once coated with the Cr layer and the protective overcoat, the dual-coated diamond insert may be air brazed to a tool substrate in a manufacturing environment using a standard braze without a vacuum furnace or special atmosphere. A method for manufacturing the diamond insert comprises the steps of depositing a chromium metal layer on a diamond substrate, depositing a substantially non-oxidizable protective layer on the metal layer and heating the dual-coated diamond article at a temperature for a sufficient time. The diamond insert is coated and heat treated in an oxygen- and nitrogen-free atmosphere to create metal carbide at the diamond-coating interface.

Claims

1. A method for manufacturing a diamond article comprising the steps of:

depositing a chromium metal layer on a diamond substrate, said metal layer and said diamond substrate forming an interface therebetween;

depositing a substantially non-oxidizable protective layer selected from the group comprising nickel (Ni) and nickel-chromium (Cv) alloy on said metal layer to form a dual-coated diamond article; and

heating said dual-coated diamond article at a temperature and for a time sufficient to form chromium carbide at the interface between said metal layer and said diamond substrate to provide adhesion of said metal layer to said substrate;

whereby said diamond article is brazable in air.

2. A method in accordance with claim 1 wherein said heating step is carried out as a single heat treatment performed on said dual-coated diamond article, and said temperature and time are sufficient to also enhance adhesion of said protective layer to said metal bonding layer.

3. A method in accordance with claim 2 wherein said heating is carried out in an atmosphere including sufficient hydrogen to prevent oxidation of said Ni and said Cr.

4. A method in accordance with claim 1 wherein said temperature is about 700°

-960°

C. said time is about 5-60 min, and said atmosphere is a hydrogen-argon mixture including an oxygen and nitrogen getter.

5. A method in accordance with claim 1 further comprising the step, after the heating step, of brazing said dual-coated diamond article to a tool substrate.

6. The method in accordance with claim 1, wherein said diamond substrate is a chemical vapor deposited diamond substrate.

7. A method in accordance with claim 1 wherein said temperature is about 700°

-960°

C., said time is about 5-60 min., and said atmosphere is hydrogen-argon mixture including an oxygen and nitrogen getter.

8. A method for manufacturing a diamond article comprising the steps of:

depositing a chromium metal layer on a diamond substrate to form a metal coated diamond substrate, said metal layer and said diamond substrate having an interface there between;

heating said metal coated diamond substrate at a temperature and for a time sufficient to form chromium carbide at the interface between said metal layer and said diamond layer;

depositing a substantially non-oxidizable protective layer selected from the group comprising nickel (Ni) and nickel-chromium (Cr) alloy on said metal layer to form a dual-coated diamond article; and

heating said dual coated diamond article at a temperature and for a time sufficient to enhance adhesion of said protective layer to said metal coated diamond substrate, whereby said diamond article is brazable.

9. A method in accordance with claim 8, wherein said protective layer is selected from the group comprising nickel (Ni) and nickel-chromium (Cr) alloy.

10. A method in accordance with claim 8 wherein said heating is carried out in an atmosphere including sufficient hydrogen to prevent oxidation of said Ni and said Cr.

11. A method in accordance with claim 8, wherein said diamond substrate is a chemical vapor deposited diamond substrate.

12. A method in accordance with claim 8 further comprising the step, after the heating step, of brazing said dual-coated diamond article to a tool substrate.