Methods of manufacturing a polycrystalline diamond compact including an at least bi-layer polycrystalline diamond table

1. A method of fabricating a polycrystalline diamond compact, the method comprising:

forming an assembly including:

a first region including diamond particles;

a substrate; and

an intermediate second region disposed between the substrate and the first region, the intermediate second region including a mixture including diamond particles and one or more sp 2 -carbon-containing additives;

subjecting the assembly to a high-pressure/high-temperature process to sinter the diamond particles of the first region and the intermediate second region in the presence of a metal-solvent catalyst to form a polycrystalline diamond table that is bonded to the substrate, the polycrystalline diamond table including:

a first polycrystalline diamond region formed at least partially from the first region and the metal-solvent catalyst; and

a second polycrystalline diamond region disposed between the first polycrystalline diamond region and the substrate, the second polycrystalline diamond region formed at least partially from the intermediate second region and the metal-solvent catalyst, the second polycrystalline diamond region having a greater diamond density than the first polycrystalline diamond region; and

leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region.

2. The method of claim 1 wherein the one or more sp 2 -carbon-containing additives of the intermediate second region includes at least one of a plurality of graphite particles, a plurality of graphene particles, a plurality of fullerene particles, or a plurality of ultra-dispersed diamond particles.

3. The method of claim 1 wherein the one or more sp 2 -carbon-containing additives of the intermediate second region includes greater than zero to about 15 weight percent of the mixture.

4. The method of claim 1 wherein the one or more sp 2 -carbon-containing additives of the intermediate second region includes about 2 weight percent to about 10 weight percent of the mixture.

5. The method of claim 1 wherein the one or more sp 2 -carbon-containing additives of the intermediate second region includes about 3 weight percent to about 6 weight percent of the mixture.

6. The method of claim 1 wherein the one or more sp 2 -carbon-containing additives of the intermediate second region includes about 5 weight percent of graphite particles.

7. The method of claim 1 wherein leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region includes leaching the metal-solvent catalyst from only the first polycrystalline diamond region.

8. The method of claim 1 wherein leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region includes leaching the metal-solvent catalyst from a depth of about 50 μm to about 400 μm.

9. The method of claim 1 wherein the first region is free of graphite, graphene, ultra-dispersed diamond particles, fullerenes, or combinations thereof.

10. The method of claim 1 wherein the first region includes a plurality of sacrificial particles mixed with the diamond particles thereof that increases the leachability of the metal-solvent catalyst from the first region compared to if the plurality of sacrificial particles were absent from the first region.

11. The method of claim 10 wherein the plurality of sacrificial particles includes particles made from at least one member selected from the group consisting titanium, vanadium, chromium, iron, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, rhenium, alloys thereof, and carbides thereof.

12. The method of claim 1 wherein the substrate includes the metal-solvent catalyst, and wherein subjecting the assembly to a high-pressure/high-temperature process includes infiltrating the metal-solvent catalyst into the first region and the second region.

13. The method of claim 1 wherein:

the diamond particles of the first region exhibits a first average particle size;

the diamond particles of the second region exhibits a second average particle size greater than the first average particle size;

the first polycrystalline diamond region exhibits a first thermal stability and a first diamond density;

the second polycrystalline diamond region exhibits a second thermal stability greater than the first thermal stability of the first polycrystalline diamond region and a second diamond density greater than the first diamond density of the first polycrystalline diamond region.

14. The method of claim 13 wherein the second diamond density is about 1 to about 10 percent greater than the first diamond density.

15. The method of claim 13 wherein the second diamond density is about 1 to about 5 percent greater than the first diamond density.

16. The method of claim 13 wherein the first polycrystalline diamond region exhibits a first thickness and the second polycrystalline diamond region exhibits a second thickness that is about 1 to about 10 times greater than the first thickness.

17. The method of claim 13 wherein the first polycrystalline diamond region exhibits a first thickness and the second polycrystalline diamond region exhibits a second thickness that is about 1 to about 8 times greater than the first thickness.

18. A method of fabricating a polycrystalline diamond compact, the method comprising;

forming an assembly including:

a first region including diamond particles;

a substrate; and

a second region disposed between the substrate and the first region, the second region including a mixture including diamond particles and one or more sp 2 -carbon-containing additives;

subjecting the assembly to a high-pressure/high-temperature process to sinter the diamond particle of the first region and the second region in the presence of a metal-solvent catalyst to form a polycrystalline diamond table that is bonded to the substrate, the polycrystalline diamond table including:

a first polycrystalline diamond region formed at least partially from the first region and the metal-solvent catalyst, the first polycrystalline diamond region exhibiting a first thermal stability and a first diamond density; and

a second polycrystalline diamond region formed at least partially from the second region and the metal-solvent catalyst, the second polycrystalline diamond region exhibiting a second thermal stability greater than the first thermal stability of the first polycrystalline diamond region and a second diamond density greater than the first diamond density of the first polycrystalline diamond region; and

leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region.

19. The method of claim 18 wherein the diamond particles of the first region exhibits a first average diamond particle size, and wherein the diamond particles of the second region exhibits a second average diamond particle size greater than the first average diamond particle size.

20. The method of claim 18 wherein the one or more sp 2 -carbon-containing additives of the second region includes at least one of a plurality of graphite particles, a plurality of graphene particles, a plurality of fullerene particles, or a plurality of ultra-dispersed diamond particles.

21. The method of claim 18 wherein the one or more sp 2 -carbon-containing additives of the second region includes greater than zero to about 15 weight percent of the mixture.

22. The method of claim 18 wherein the one or more sp 2 -carbon-containing additives of the second region includes about 2 weight percent to about 10 weight percent of the mixture.

23. The method of claim 18 wherein leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region includes leaching the metal-solvent catalyst from only the first polycrystalline diamond region.

24. The method of claim 18 wherein leaching the metal-solvent catalyst from at least a portion of the first polycrystalline diamond region to form an at least partially leached region includes leaching the metal-solvent catalyst to a depth of about 50 μm to about 400 μm.

25. A method of fabricating a polycrystalline diamond compact, the method comprising;

forming an assembly including:

a first region including diamond particles exhibiting a first average diamond particle size;

a substrate; and

a second region disposed between the substrate and the first region, the second region including a mixture including one or more sp 2 -carbon-containing additives and diamond particles exhibiting a second average diamond particles size greater than the first average diamond particle size; and

subjecting the assembly to a high-pressure/high-temperature process to sinter the diamond particle of the first region and the second region in the presence of a metal-solvent catalyst to form a polycrystalline diamond table that is bonded to the substrate, the polycrystalline diamond table including:

a first polycrystalline diamond region formed at least partially from the first region and the metal-solvent catalyst, the first polycrystalline diamond region exhibiting a first thermal stability and a first diamond density; and

a second polycrystalline diamond region formed at least partially from the second region and the metal-solvent catalyst, the second polycrystalline diamond region exhibiting a second thermal stability greater than the first thermal stability of the first polycrystalline diamond region and a second diamond density greater than the first diamond density of the first polycrystalline diamond region.

26. The method of claim 25 further comprising leaching the metal-solvent catalyst from only the first polycrystalline diamond region to form an at least partially leached region.