Element containing thermally stable polycrystalline diamond material and methods and assemblies for formation thereof
The disclosure provides a super abrasive element containing a substantially catalyst-free thermally stable polycrystalline diamond (TSP) body having pores and a contact surface, a base adjacent the contact surface of the TSP body; and an infiltrant material infiltrated in the base and in the pores of the TSP body at the contact surface. The disclosure additionally provides earth-boring drill bits and other devices containing such super abrasive elements. The disclosure further provides methods and mold assemblies for forming such super abrasive elements via infiltration and hot press methods.
1. A method of forming a super abrasive element comprising:
assembling an assembly comprising:
a mold having a bottom;
a thermally stable polycrystalline diamond (TSP) body having pores and a contact surface and located in the bottom of the mold;
a matrix powder disposed adjacent the contact surface and above the TSP body in the mold, the matrix powder operable to form a base after heating; and
an infiltrant material disposed in the matrix powder in the mold;
heating the assembly to a temperature up to 1200° C. at a pressure and for a time sufficient for the infiltrant material to infiltrate the matrix powder to form a base and pores of the TSP body at the contact surface to form an infiltrant material-containing region, while leaving an infiltrant-free region at a working surface of the TSP body, wherein the infiltrant material infiltrates the pores of the TSP body to a depth from the contact surface of 100 μm or less; and
cooling the assembly to form a super abrasive element,
wherein the matrix powder comprises a carbide-containing or carbide-forming powder.
2. The method according to claim 1 , further comprising forming the TSP body prior to assembling the assembly.
3. The method according to claim 1 , wherein forming the TSP body comprises leaching a polycrystalline diamond compact (PCD) having a diamond matrix and an interstitial matrix containing catalyst to remove the catalyst from the interstitial matrix and form pores.
4. The method according to claim 3 , wherein leaching comprises leaching with an acid-based leaching agent comprising FeCl 3 .
5. The method according to claim 3 , further comprising removing at least 85% of the catalyst from the PCD.
6. The method according to claim 1 , further comprising infiltrating at least pores exposed on the contact surface with infiltrant material.
7. The method according to claim 1 , wherein assembling further comprises disposing a carbide insert in the matrix powder.
8. The method according to claim 1 , further comprising cleaning the contact surface of the TSP body prior to assembling the assembly.
9. The method according to claim 1 , further comprising cooling the assembly from the bottom.
10. The method according to claim 1 , wherein the TSP body comprises diamond grains having an average grain size and wherein the infiltrant material is infiltrated in the pores of the TSP body to a depth from the contact surface of four average grain sizes or less.
11. The method according to claim 1 , wherein the TSP body comprises diamond grains having an average grain size and wherein the infiltrant material is infiltrated in the pores of the TSP body to a depth from the contact surface of two average grain sizes or less.
12. The method according to claim 1 , wherein the TSP body comprises diamond grains having an average grain size and wherein the infiltrant material is infiltrated in the pores of the TSP body to a depth from the contact surface of one average grain size or less.
13. The method according to claim 1 , wherein the TSP body comprises diamond grains having an average grain size and wherein the infiltrant material is infiltrated in the pores of the TSP body to a depth from the contact surface of half an average grain size or less.
14. The method according to claim 1 , wherein the TSP body comprises diamond grains having an average grain size and wherein the infiltrant material is infiltrated in the pores of the TSP body to a depth from the contact surface of one quarter of an average grain size or less.
15. The method according to claim 1 , wherein the contact surface is a non-planar surface.
16. The method according to claim 1 , wherein heating the assembly to a temperature at a pressure and for a time sufficient for the infiltrant material to infiltrate the matrix powder forms a base from the matrix powder, and wherein the TSP body comprises at least one feature to mechanically enhance attachment of the TSP body to the base.
17. The method according to claim 1 , wherein the matrix powder further comprises an erosion resistant material selected from the group consisting of carbide, tungsten, tungsten carbide, synthetic diamond, natural diamond, or nickel and any combinations thereof.
18. The method according to claim 1 , wherein the super abrasive element formed is a cutter for an earth-boring drill bit.
19. The method according to claim 3 , further comprising removing at least 95% of the catalyst from the PCD.
20. The method according to claim 1 , wherein the contact surface of the TSP comprises an attachment layer.
21. The method according to claim 1 , wherein the matrix powder further comprises a material selected from the group consisting of chromium, iron, copper, manganese, phosphorus, oxygen, zinc, tin, cadmium, lead, bismuth, tellurium, and any combinations thereof.