System, method, and apparatus for enhancing the durability of earth-boring bits with carbide materials

1. A drill bit, comprising:

a drill bit body having a cutting component; and

at least a portion of the drill bit formed from a composite material comprising crystals of tungsten carbide and a binder, the crystals having a generally spheroidal shape, a mean grain size range of about 0.5 to 8 microns, and a size-distribution that is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns.

2. A drill bit according to claim 1 , wherein the binder is one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6%to 8% cobalt.

3. A drill bit according to claim 1 , wherein the composite material comprises bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns , and a smaller size of the crystals has a mean size of about 1 micron.

4. A drill bit according to claim 1 , wherein the composite material comprises tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of ≦8 microns , an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns.

5. A drill bit according to claim 1 , wherein the cutting component comprises polycrystalline diamond (PCD) cutters having substrates with diamond layers formed thereon, and said at least a portion of the drill bit comprises one of the substrates, a component of hardfacing on the drill bit, and a material used to form at least a portion of the drill bit.

6. A drill bit according to claim 1 , wherein the drill bit comprises a matrix head formed at least in part from the composite material.

7. A drill bit according to claim 1 , wherein the drill bit comprises a rolling cone drill bit, and said at least a portion of the drill bit comprises one of a component of hardfacing on the drill bit body, and a material used to form at least a portion of the drill bit.

8. A drill bit according to claim 1 , wherein the cutting component comprises milled teeth, and said at least a portion of the drill bit comprises one of a component of hardfacing on the milled teeth, portions of the drill bit body, and a material used to form at least a portion of the drill bit.

9. A drill bit, comprising:

a drill bit body having a cutting component; and

a hardfacing on the drill bit comprising a composite material comprising crystals of tungsten carbide and a binder, the crystals having a generally spheroidal shape, a mean grain size range of about 0.5 to 8 microns, and a distribution of which is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns.

10. A drill bit according to claim 9 , wherein the composite material comprises bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns , and a smaller size of the crystals has a mean size of about 1 micron.

11. A drill bit according to claim 9 , wherein the composite material comprises tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of ≦8 microns, an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns.

12. A drill bit according to claim 9 , wherein the cutting component comprises polycrystalline diamond (PCD) cutters having substrates with diamond layers formed thereon, the substrates comprising the composite material.

13. A drill bit according to claim 9 , wherein the drill bit comprises a matrix head comprising the composite material, and the binder is one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6%to 8% cobalt.

14. A drill bit according to claim 9 , wherein the drill bit comprises a rolling cone drill bit, and the composite material forms at least a portion of the drill bit.

15. A drill bit according to claim 9 , wherein the cutting component comprises milled teeth having the hardfacing, and the composite material forms at least a portion of the drill bit.

16. A method of making a drill bit, comprising:

providing crystals of tungsten carbide having a mean grain size range of about 0.5 to 8 microns, a distribution of which is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns;

forming a bulk composite of the crystals and a binder;

crushing the bulk composite to form crushed particles having non-uniform, irregular shapes;

sorting a particular size of the crushed particles by size to define a composite material;

fabricating a drill bit; and

forming at least a portion of the drill bit from the composite material.

17. A method according to claim 16 , wherein forming a bulk composite of the crystals and a binder comprises forming a billet of the crystals and binder, and further comprising sintering the billet.

18. A method according to claim 16 , wherein forming at least a portion of the drill bit from the composite material comprises forming a hardfacing on the drill bit comprising the composite material.

19. A method according to claim 16 , wherein forming a bulk composite of the crystals and a binder comprises selecting the binder from one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt.

20. A method according to claim 16 , wherein providing crystals of tungsten carbide comprises formulating bi-modal, spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns , and a smaller size of the crystals has a mean size of about 1 micron.

21. A method according to claim 16 , wherein providing crystals of tungsten carbide comprises formulating tri-modal, spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of ≦8 microns , an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns.

22. A method according to claim 16 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprise fabricating polycrystalline diamond (PCD) cutters having substrates with diamond layers formed thereon, and forming one of the substrates, a component of hardfacing on the drill bit, and a material used to form at least a portion of the drill bit body from the composite material.

23. A method according to claim 16 , wherein: fabricating a drill bit and forming at least portion of the drill bit from the composite material comprise fabricating the drill bit with a matrix head formed at least in part from the composite material.

24. A method according to claim 16 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprises fabricating the drill bit as a rolling cone drill bit, and said at least a portion of the drill bit comprises one of a component of hardfacing on a drill bit body, and a material used to form at least a portion of the drill bit.

25. A method according to claim 16 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprise fabricating the drill bit with milled teeth, and said at least a portion of the drill bit comprises one of a component of hardfacing on the milled teeth, portions of the drill bit body, and a material used to form at least a portion of the drill bit.

26. A method of making a drill bit, comprising:

providing a composite material of a binder and crystals of tungsten carbide having a mean grain size range of about 0.5 to 8 microns, a distribution of which is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns;

fabricating a drill bit; and

forming at least a portion of the drill bit from the composite material.

27. A method according to claim 26 , wherein forming at least a portion of the drill bit from the composite material comprises forming a hardfacing on the drill bit comprising the composite material.

28. A method according to claim 26 , wherein providing a composite material of a binder and crystals of tungsten carbide comprises selecting the binder from one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt.

29. A method according to claim 26 , wherein providing a composite material of a binder and crystals of tungsten carbide comprises formulating bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns , and a smaller size of the crystals has a mean size of about 1 micron.

30. A method according to claim 26 , wherein providing a composite material of a binder and crystals of tungsten carbide comprises formulating tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of ≦8 microns , an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns.

31. A method according to claim 26 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprise fabricating polycrystalline diamond (PCD) cutters having substrates with diamond layers formed thereon, and forming one of the substrates, a component of hardfacing on the drill bit, and a material used to form at least a portion of the drill bit body from the composite material.

32. A method according to claim 26 , wherein: fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprise fabricating the drill bit with a matrix head formed at least in part from the composite material.

33. A method according to claim 26 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprises fabricating the drill bit as a rolling cone drill bit, and said at least a portion of the drill bit comprises one of a component of hardfacing on a drill bit body, and a material used to form at least a portion of the drill bit.

34. A method according to claim 26 , wherein fabricating a drill bit and forming at least a portion of the drill bit from the composite material comprise fabricating the drill bit with milled teeth, and said at least a portion of the drill bit comprises one of a component of hardfacing on the milled teeth, portions of the drill bit body, and a material used to form at least a portion of the drill bit.