Hard-facing for downhole tools and matrix bit bodies with enhanced wear resistance and fracture toughness

Patent metadata

Field	Value
Publication number	US-9604345-B2
Application number	US-201314070003-A
Country	US
Kind code	B2
Filing date	Nov 1, 2013
Priority date	Nov 1, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A composite material and a methods of making and using the composite material, wherein the composite material provides improved wear resistance and fracture toughness to hard-facing and matrix materials for down hole drilling tools.

First claim

What is claimed is:

1. A composite material comprising:
a first material comprising a plurality of grains of eutectic WC and W2C, wherein each of the plurality of grains of the first material has an elongated microstructure with a thickness less than about 2 microns and an aspect ratio of about 10 to about 100; and
a second material comprising a shell around said first material, wherein said shell has a thickness of about 0.1 micron to about 35 micron.

2. The composite material of claim 1 , wherein said first material comprises about 10 wt. % WC to about 40 wt. % WC.

3. The composite material of claim 2 , wherein said first material comprises about 20 wt. % WC to about 37 wt. % WC.

4. The composite material of claim 1 , wherein said first material comprises about 50 wt. % W2C to about 65 wt. % W2C.

5. The composite material of claim 4 , wherein said first material comprises about 55 wt. % W2C to about 62 wt. % W2C.

6. The composite material of claim 1 , wherein said first material comprises about 3.8 wt. % to about 4.2 wt. % of carbon.

7. The composite material of claim 1 , wherein said first material comprises an inner core structure.

8. The composite material of claim 7 , wherein said inner core is spherical.

9. The composite material of claim 8 , wherein said inner core structure comprises a needle like or a plate like elongated microstructure.

10. The composite material of claim 1 , wherein said second material comprises WC.

11. The composite material of claim 1 , wherein said composite material comprises a Vickers hardness of 1800 to 3000.

12. A method of making a composite material comprising:
mixing:
a carbide material, wherein said carbide material comprises a plurality of grains of carbide material, wherein each of the plurality of grains of the carbide material has an elongated microstructure with a thickness less than about 2 microns and with an aspect ratio of about 10 to about 100; and
a carbon rich material, to form a first mixture;

heating said mixture under vacuum; and
cooling said mixture under vacuum to form a composite material.

13. The method of claim 12 , wherein said carbide material is eutectic WC/W2C.

14. The method of claim 12 , wherein said carbide material comprises about 55 wt. % W2C to about 62 wt. % W2C.

15. The method of claim 12 , wherein said carbide material comprises about 20 wt. % WC to about 37 wt. % WC.

16. The method of claim 12 , wherein said carbide material further comprises spherical particles.

17. The method of claim 16 , wherein the spherical particles are about 50 microns to 1200 microns in size.

18. The method of claim 12 , wherein said carbon rich material is at least one of: air, a carbon rich gas; CO, CO2, CO/CO2, alkanes, alkenes, coarse carbon black, or fine carbon black.

19. The method of claim 18 , wherein said carbon rich material is fine carbon black.

20. The method of claim 19 , wherein said fine carbon black comprises about 1 wt % to about 4 wt. % of the mixture.

21. The method of claim 19 , wherein said carbon black is about 0.1 microns to about 100 microns in size.

22. The method of claim 12 , wherein said heating is for about 1 to about 24 hrs.

23. The method of claim 12 , wherein said heating is for less than about 8 hrs.

24. The method of claim 12 , further comprises after said mixing, placing said mixture in an inert vessel.

25. The method of claim 12 , wherein said composite material comprises a spherical inner core structure; and further comprises an outer shell, wherein said shell is about 2 micron to about 10 microns thick.

26. The method of claim 25 , wherein said shell is about 5 microns to about 7 microns thick.

27. The method of claim 25 , wherein said spherical inner core structure comprises WC/W2C.

28. The method of claim 25 , wherein said shell is comprises WC.

29. The method of claim 27 , wherein said spherical inner core structure comprises a needle like or a plate like elongated microstructure.

30. The method of claim 25 , wherein said spherical inner core structure is about 50 microns to about 1200 microns in size.

31. The method of claim 30 , wherein said spherical inner core structure is about 100 microns to about 300 microns in size.

32. The method of claim 25 , wherein said spherical inner core structure has a Vickers hardness number of greater than 2000, and wherein said shell has a Vickers hardness number of 1800 to 3000.

33. The method of claim 12 , wherein said composite material is a matrix drill body.

34. The method of claim 12 , wherein said composite material is a hard-facing surface.

35. A drill bit for drilling a borehole in earthen formations comprising:
a bit body;
a coating applied to at least a portion of the bit body, wherein the coating is a composite material comprising:
a first material comprising a plurality of eutectic WC and W2C, wherein each of the plurality of grains of the first material has a needle-like structure with a thickness less than about 2 microns and with an aspect ratio of about 10 to about 100; and
a second material comprising a shell around said first material, wherein said shell has a thickness of about 0.1 micron to about 35 micron.

36. The composite material of claim 1 , wherein said first material comprises a spherical inner core structure having a size about 100 microns to about 300 microns; and
wherein said shell has a thickness of about 2 micron to about 10 microns.

Assignees

• Nat Oilwell Dht Lp

Inventors

• Wang Ying
• Arceneaux Sr Wesley Craig
• Sue Jiinjen Albert
• Sreshta Harold A

Classifications

• C22C1/056

  using gas · 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

• C04B35/6286

  Carbides · CPC title

• C04B2235/528

  Spheres · CPC title

• C01B31/34

  Chemistry & Metallurgy · mapped topic