Methods of fabricating polycrystalline diamond, and cutting elements and earth-boring tools comprising polycrystalline diamond

Patent metadata

Field	Value
Publication number	US-10066441-B2
Application number	US-201615342888-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Apr 14, 2010
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

Methods of fabricating polycrystalline diamond include subjecting a particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular diamond-to-diamond bonds. Before being subjected to HPHT conditions, the particle mixture includes a plurality of non-diamond nanoparticles, diamond nanoparticles, and diamond grit. The non-diamond nanoparticles includes carbon-free cores and at least one functional group attached to the cores. Cutting elements for use in an earth-boring tool include a polycrystalline diamond material formed by such processes. Earth-boring tools include such cutting elements.

First claim

What is claimed is:

1. A method of fabricating polycrystalline diamond, comprising:
subjecting a particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular diamond-to-diamond bonds, wherein the particle mixture comprises, before subjecting to the HPHT conditions:
a plurality of non-diamond nanoparticles, each comprising a carbon-free core and at least one functional group attached thereto;
diamond nanoparticles; and
diamond grit.

2. The method of claim 1 , further comprising functionalizing at least some of the plurality of non-diamond nanoparticles with functional groups formulated to form diamond.

3. The method of claim 1 , further comprising functionalizing at least some of the plurality of non-diamond nanoparticles with functional groups comprising carbon and hydrogen.

4. The method of claim 1 , wherein subjecting a particle mixture to HPHT conditions comprises at least partially decomposing the at least one functional group.

5. The method of claim 4 , wherein at least partially decomposing the at least one functional group comprises forming elemental carbon and elemental hydrogen.

6. The method of claim 1 , further comprising exposing the carbon-free cores to a methane gas environment before subjecting the particle mixture to HPHT conditions.

7. The method of claim 6 , wherein exposing the carbon-free cores to a methane gas environment comprises forming carbon-based functional groups on the carbon-free cores by chemical vapor deposition (CVD).

8. The method of claim 1 , further comprising encapsulating at least some of the carbon-free cores in a polymer before subjecting the particle mixture to HPHT conditions.

9. The method of claim 1 , further comprising forming the plurality of non-diamond nanoparticles to have a combination of at least two different functional groups.

10. The method of claim 1 , wherein the at least one functional group comprises carbon atoms and hydrogen atoms, and wherein a ratio of the carbon atoms to the hydrogen atoms is within a range from about 1:1 to about 1:3.

11. The method of claim 1 , further comprising forming agglomerates comprising the plurality of non-diamond nanoparticles and the diamond nanoparticles.

12. The method of claim 11 , further comprising mixing the agglomerates with the diamond grit.

13. The method of claim 1 , further comprising encapsulating the particle mixture and a hydrocarbon substance in a canister before subjecting the particle mixture to HPHT conditions.

14. A cutting element for use in an earth-boring tool, the cutting element comprising a polycrystalline diamond material formed by a method comprising:
subjecting a particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular diamond-to-diamond bonds, wherein the particle mixture comprises, before subjecting to the HPHT conditions:
a plurality of non-diamond nanoparticles, each comprising a carbon-free core and at least one functional group attached thereto;
diamond nanoparticles; and

diamond grit.

15. The cutting element of claim 14 , further comprising a substrate, wherein the polycrystalline diamond material is bonded to the substrate.

16. The cutting element of claim 15 , wherein the substrate comprises a generally cylindrical body of cobalt-cemented tungsten carbide.

17. The cutting element of claim 14 , wherein the cutting element comprises a network of diamond grains having a bimodal size distribution.

18. The cutting element of claim 17 , wherein the network of diamond grains comprises a first plurality of grains and a second plurality of grains, the first plurality of grains having an average particle dimension from about 1 μm to about 500 μm, and the second plurality of grains having an average particle dimension of about 500 nm or less.

19. An earth-boring tool comprising a cutting element, the cutting element comprising a polycrystalline diamond material formed by a method comprising:
subjecting a particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular diamond-to-diamond bonds, wherein the particle mixture comprises, before subjecting to the HPHT conditions:
a plurality of non-diamond nanoparticles, each comprising a carbon-free core and at least one functional group attached thereto;
diamond nanoparticles; and

diamond grit.

20. The earth-boring tool of claim 19 , wherein the polycrystalline diamond comprises a generally cylindrical body bonded to a substrate comprising cobalt-cemented tungsten carbide.

Assignees

• Baker Hughes Inc

Inventors

• Chakraborty Soma
• Digiovanni Anthony A
• Agrawal Gaurav

Classifications

• B22F1/102

  Metallic powder coated with organic material · CPC title

• C04B35/645

  Pressure sintering · CPC title

• C22C1/051

  Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title

• C04B2235/5427

  millimeter or submillimeter sized, i.e. larger than 0,1 mm · CPC title