POLYCRYSTALLINE DIAMOND CUTTING ELEMENTS WITH ENGINEERED POROSITY AND METHOD FOR MANUFACTURING SUCH CUTTING ELEMENTS

• US 20100320006A1
• Filed: 06/18/2010
• Published: 12/23/2010
• Est. Priority Date: 06/18/2009
• Status: Active Grant

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Smith International Incorporated (Schlumberger NV)
• Inventors: FAN, GUOJIANG, Yu, Feng, Fang, Yi, Cariveau, Peter T., Belnap, J. Daniel
• Granted Patent: US 8,783,389 B2
• Time in Patent Office: Days
• US Class Current: 175/428
• CPC Class Codes: B24D 18/0009 using moulds or presses
• CPC Class Codes: B24D 18/0027 by impregnation
• CPC Class Codes: B24D 99/005 Segments of abrasive wheels
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/28 for etching iron group metals
• CPC Class Codes: E21B 10/36 Percussion drill bits with helical conveying portion E21B10/445; characterised by wear resisting parts E21B10/46
• CPC Class Codes: E21B 10/55 with preformed cutting elements
• CPC Class Codes: E21B 10/567 with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts

Abstract

A method for facilitating infiltration of an infiltrant material into a TSP material during re-bonding of the TSP material to a substrate, by enhancing the porosity of the TSP material near the interface with the substrate is provided. Cutting elements formed by such method and downhole tools including such cutting elements are also provided.

Claims

1. A method of forming a thermally stable polycrystalline diamond cutting element, comprising:

mixing diamond particles and a filler material to create a diamond powder mixture, wherein the diamond powder mixture comprises a first portion with the filler material and a second portion with less filler material than the first portion, the first portion being at least 25% of a volume of the diamond powder mixture;

sintering the diamond powder mixture at high temperature and high pressure to form a polycrystalline diamond material;

removing the filler material from the polycrystalline diamond material to form a thermally stable polycrystalline diamond material having a differential porosity of at least 1.6% between the first and second portions; and

bonding the thermally stable material to a substrate, wherein bonding comprises infiltrating the first portion with an infiltrant material from the substrate.

2. The method of claim 1, wherein bonding comprises arranging the thermally stable material and the substrate such that the first portion of the thermally stable material is proximate the substrate.

3. The method of claim 1, wherein the filler material comprises cobalt.

4. The method of claim 1, wherein the filler material comprises tungsten carbide.

5. The method of claim 4, wherein the filler material comprises 5% by weight tungsten carbide in the first portion.

6. The method of claim 1, wherein mixing the diamond particles and the filler material comprises forming a gradient of an amount of filler material in the diamond powder mixture.

7. The method of claim 1, wherein the first portion forms a first layer of the thermally stable material nearest the substrate, and the second portion forms a second layer of the thermally stable material opposite the substrate.

8. The method of claim 7, wherein the first and second layers are approximately the same size.

9. The method of claim 1, wherein the first portion of the diamond powder mixture has a domed shape.

10. The method of claim 1, wherein the second portion comprises a depression and wherein the first portion comprises a projection, wherein the projection is received in said depression.

11. The method of claim 1, wherein the first portion has at least 4% filler material by weight.

12. The method of claim 1, wherein, after removing the filler material, the first portion comprises pores occupying about 9% of a volume of the first portion.

13. The method of claim 1, wherein the differential porosity is at least 2.6%.

14. A cutting element comprising:

a substrate; and

a thermally stable polycrystalline diamond body bonded to the substrate,

wherein the thermally stable polycrystalline diamond body comprises;

a working surface opposite the substrate;

a material microstructure comprising a plurality of bonded-together diamond crystals, and pores between the diamond crystals, the pores being substantially free of a catalyst material;

a first portion of the material microstructure proximate the substrate and having a porosity; and

a second portion of the material microstructure proximate the working surface and having a porosity,

wherein the first portion occupies at least 25% of a volume of the polycrystalline diamond body,

wherein the first portion comprises an infiltrant material in one or more of the pores between the diamond crystals, and

wherein the material microstructure has a differential porosity of at least 1.6% between the first and second portions when said porosities are measured without said infiltrant.

15. The cutting element of claim 14, wherein the first portion comprises a first layer of the polycrystalline diamond body and the second portion comprises a second layer of the polycrystalline diamond body, and wherein the first and second layers meet along an interface.

16. The cutting element of claim 15, wherein the interface is domed.

17. The cutting element of claim 15, wherein the interface is planar.

18. The cutting element as recited in claim 15, wherein the second layer comprises a depression and wherein the first layer comprises a projection received within said depression.

19. The cutting element of claim 14, wherein the differential porosity is at least 2.6%.

20. The cutting element of claim 14, wherein the differential porosity is at least 3.4%.

21. The cutting element of claim 14, wherein one or more pores in the first portion comprise a trace amount of a filler material, the filler material being selected from the group consisting of tungsten carbide, silicone carbide, and metals not in Group VIII of the Periodic Table.

22. The cutting element of claim 21, wherein the filler material is tungsten carbide.

23. The cutting element of claim 14, wherein the second portion comprises the infiltrant material in one or more of the pores between the diamond crystals.

24. The cutting element of claim 23, wherein the working surface comprises the infiltrant material in one or more of the pores between the diamond crystals.

25. The cutting element of claim 14, wherein the first portion comprises a first layer and the second portion comprises a second layer, and wherein the first and second layers are each approximately 50% of the volume of the polycrystalline diamond body.

26. A downhole tool comprising a tool body and at least one cutting element as claimed in claim 14 disposed thereon.

27. The downhole tool of claim 26, wherein the downhole tool comprises a drill bit.

28. A cutting element comprising:

a substrate; and

a thermally stable polycrystalline diamond body bonded to the substrate,

wherein the thermally stable polycrystalline diamond body comprises;

a working surface opposite the substrate;

a material microstructure comprising a plurality of bonded-together diamond crystals, and pores between the diamond crystals, the pores being substantially free of a catalyst material;

a first portion of the material microstructure proximate the substrate having a porosity and comprising a projection; and

a second portion of the material microstructure proximate the working surface having a porosity and comprising a depression receiving said projection,

wherein the first portion comprises an infiltrant material in one or more of the pores between the diamond crystals, and

wherein the material microstructure has a differential porosity between the first and second portions when said porosities are measured without said infiltrant.

29. The cutting element of claim 28, wherein the differential porosity is at least 1.6% between the first and second portions.

30. The cutting element of claim 28, wherein the depression is complementary to said projection.

31. The cutting element of claim 28, wherein the projection is domed shaped.

32. The cutting element of claim 28, wherein the first portion has a greater porosity than the second portion.

33. A downhole tool comprising a tool body and at least one cutting element as claimed in claim 28 disposed thereon.

34. The downhole tool of claim 33, wherein the downhole tool comprises a drill bit.