Polycrystalline diamond compacts and earth-boring tools including such compacts
View Patent ↗A polycrystalline diamond compact includes a polycrystalline diamond material having a plurality of grains of diamond bonded to one another by inter-granular bonds and an intermetallic gamma prime (γ′) or κ-carbide phase disposed within interstitial spaces between the inter-bonded diamond grains. The ordered intermetallic gamma prime (γ′) or κ-carbide phase includes a Group VIII metal, aluminum, and a stabilizer. An earth-boring tool includes a bit body and a polycrystalline diamond compact secured to the bit body. A method of forming polycrystalline diamond includes subjecting diamond particles in the presence of a metal material comprising a Group VIII metal and aluminum to a pressure of at least 4.5 GPa and a temperature of at least 1,000° C. to form inter-granular bonds between adjacent diamond particles, cooling the diamond particles and the metal material to a temperature below 500° C., and forming an intermetallic gamma prime (γ′) or κ-carbide phase adjacent the diamond particles.
1. A polycrystalline diamond compact, comprising:
a polycrystalline diamond material comprising a plurality of grains of diamond bonded to one another by inter-granular bonds; and
a structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase disposed within interstitial spaces between the inter-bonded diamond grains, the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprising a Group VIII metal, aluminum, and a stabilizer.
2. The polycrystalline diamond compact of claim 1 , wherein the stabilizer comprises a material selected from the group consisting of titanium, nickel, tungsten, and carbon.
3. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises a metastable Co 3 Al phase stabilized by the stabilizer.
4. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises a metastable (Co x Ni 3-x )Al phase stabilized by the stabilizer.
5. The polycrystalline diamond compact of claim 1 , wherein the stabilizer comprises carbon.
6. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase exhibits an ordered face-centered cubic structure.
7. The polycrystalline diamond compact of claim 1 , wherein the polycrystalline diamond material is disposed over a substrate comprising the Group VIII metal.
8. The polycrystalline diamond compact of claim 1 , wherein the polycrystalline diamond material is substantially free of elemental iron, cobalt, and nickel.
9. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises a metastable Co x Al y phase having less than about 13% Co by weight.
10. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises a metastable CO x Al y phase having less than about 50 mol% Al.
11. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises a metastable (Co,Ni) 3 Al phase stabilized by the stabilizer.
12. The polycrystalline diamond compact of claim 1 , wherein the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase comprises an alloy of about 13.5% Al by weight.
13. The polycrystalline diamond compact of claim 1 , wherein the inter-bonded diamond grains are at least substantially coated by the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase within the interstitial spaces, the structurally ordered intermetallic gamma prime (γ′) or κ-carbide phase providing a barrier between the inter-bonded diamond grains and any catalyst material located within the interstitial spaces.
14. A polycrystalline diamond compact, comprising:
a polycrystalline diamond material comprising a plurality of grains of diamond bonded to one another by inter-granular bonds; and
an intermetallic gamma prime (γ′) or κ-carbide phase disposed within interstitial spaces between the inter-bonded diamond grains, the intermetallic gamma prime (γ′) or κ-carbide phase comprising a Group VIII metal, aluminum, and a stabilizer, wherein the intermetallic gamma prime (γ′) or κ-carbide phase is structurally ordered.
15. A polycrystalline diamond compact, comprising:
a polycrystalline diamond material comprising a plurality of grains of diamond bonded to one another by inter-granular bonds; and
an intermetallic gamma prime (γ′) or κ-carbide phase disposed within interstitial spaces between the inter-bonded diamond grains, the intermetallic gamma prime (γ′) or κ-carbide phase comprising a Group VIII metal, aluminum, and a stabilizer, wherein the intermetallic gamma prime (γ′) or κ-carbide phase is structurally disordered.
16. An earth-boring tool, comprising:
a bit body; and
a polycrystalline diamond compact secured to the bit body, the polycrystalline diamond compact comprising:
a polycrystalline diamond material comprising a plurality of grains of diamond bonded to one another by inter-granular bonds; and
an intermetallic gamma prime (γ′) or κ-carbide phase disposed within interstitial spaces between the inter-bonded diamond grains, the intermetallic gamma prime (γ′) or κ-carbide phase comprising a Group VIII metal, aluminum, and a stabilizer, wherein a lattice of at least a portion of the intermetallic gamma prime (γ′) or κ-carbide phase exhibits an ordered configuration.
17. The earth-boring tool of claim 16 , wherein the polycrystalline diamond material is substantially free of a catalyst material without leaching.
18. The earth-boring tool of claim 16 , wherein the intermetallic gamma prime (γ′) or κ-carbide phase is substantially evenly distributed throughout the polycrystalline diamond material of the polycrystalline diamond compact.
19. The earth-boring tool of claim 16 , wherein the plurality of grains of diamond of the polycrystalline diamond material comprises nanodiamond grains.
20. The earth-boring tool of claim 13 , wherein the intermetallic gamma prime (γ′) or κ-carbide phase comprises (Co,Ni) 3 Al.