Polycrystalline diamond compact including a non-uniformly leached polycrystalline diamond table and applications therefor

A rotary drill bit, comprising:

• a bit body configured to engage a subterranean formation;
• and
• a plurality of polycrystalline diamond cutting elements affixed to the bit body, at least one of the polycrystalline diamond cutting elements including:
• a substrate;
• and
• a polycrystalline diamond table bonded to the substrate, the polycrystalline diamond table defining a substantially planar upper surface, at least one peripheral surface, and a chamfer extending between the substantially planar upper surface and the at least one peripheral surface, the polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions, the polycrystalline diamond table further including:
• a first region adjacent to the substrate that includes metal-solvent catalyst disposed interstitially between the bonded diamond grains thereof;
• and
• a leached second region extending inwardly from the substantially planar upper surface and the at least one peripheral surface that is depleted of the metal-solvent catalyst, the leached second region exhibiting a leach depth profile having a maximum leach depth that is at least about 300 μm as measured from the substantially planar upper surface, a leach depth of the leach depth profile decreasing with lateral distance from a central axis of the polycrystalline diamond table and toward the at least one peripheral surface.

A polycrystalline diamond compact, comprising:

• a substrate;
• and
• a pre-sintered polycrystalline diamond table integrally formed with and bonded to the substrate, the pre-sintered polycrystalline diamond table defining a substantially planar upper surface, at least one peripheral surface, and a chamfer extending between the substantially planar upper surface and the at least one peripheral surface, the pre-sintered polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions, the pre-sintered polycrystalline diamond table further including:
• a first region adjacent to the substrate that includes metal-solvent catalyst disposed interstitially between the bonded diamond grains thereof;
• and
• a leached second region extending inwardly from the upper surface, from the chamfer, and from the at least one peripheral surface, the leached second region being depleted of the metal-solvent catalyst, the leached second region exhibiting a leach depth profile having a maximum leach depth that is at least about 250 μm as measured from the substantially planar upper surface, a leach depth of the leach depth profile decreasing with lateral distance from a central axis of the pre-sintered polycrystalline diamond table and toward the at least one peripheral surface.

A rotary drill bit, comprising:

• a bit body configured to engage a subterranean formation;
• and
• a plurality of polycrystalline diamond cutting elements affixed to the bit body, at least one of the polycrystalline diamond cutting elements including:
• a substrate;
• and
• a pre-sintered polycrystalline diamond table integrally formed with and bonded to the substrate, the pre-sintered polycrystalline diamond table defining a substantially planar upper surface, at least one peripheral surface, and a chamfer extending between the substantially planar upper surface and the at least one peripheral surface, the pre-sintered polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions, the pre-sintered polycrystalline diamond table further including:
• a first region adjacent to the substrate that includes metal-solvent catalyst disposed interstitially between the bonded diamond grains thereof;
• and
• a leached second region extending inwardly from the upper surface, from the at least one peripheral surface, and from the chamfer, the leached second region being depleted of the metal-solvent catalyst, the leached second region exhibiting a leach depth profile having a maximum leach depth that is at least about 250 μm as measured from the substantially planar upper surface, a leach depth of the leach depth profile decreasing with lateral distance from a central axis of the pre-sintered polycrystalline diamond table and toward the at least one peripheral surface.

A method of fabricating a leached polycrystalline diamond compact, comprising:

• providing a polycrystalline diamond compact including:
• a substrate;
• and
• a polycrystalline diamond table bonded to the substrate, the polycrystalline diamond table defining a substantially planar upper surface, at least one peripheral surface, at least one peripheral surface, and a chamfer extending between the substantially planar upper surface and the at least one peripheral surface, the polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions, the polycrystalline diamond table further including metal-solvent catalyst disposed interstitially between at least a portion of the bonded diamond grains thereof;
• and
• leaching the metal-solvent catalyst from a region of the polycrystalline diamond table so that the region is depleted of the metal-solvent catalyst to a maximum leach depth that is greater than about 300 μm as measured from the substantially planar upper surface, a leach depth of the region decreasing with lateral distance from a central axis of the polycrystalline diamond table and toward the at least one peripheral surface.

A method of fabricating a leached polycrystalline diamond compact, comprising:

• providing a polycrystalline diamond compact including:
• a substrate;
• and
• a pre-sintered polycrystalline diamond table bonded to the substrate, the pre-sintered polycrystalline diamond table defining a substantially planar upper surface, at least one peripheral surface, and a chamfer extending between the substantially planar upper surface and the at least one peripheral surface, the pre-sintered polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions, the pre-sintered polycrystalline diamond table further including metal-solvent catalyst disposed interstitially between at least a portion of the bonded diamond grains thereof;
• wherein the polycrystalline diamond compact is formed according to a method including subjecting an at least partially leached polycrystalline diamond table that includes a plurality of interstitial regions therein and the substrate to a high-pressure/high-temperature process to infiltrate the at least partially leached polycrystalline diamond table with the metal-solvent catalyst;
• and
• leaching the metal-solvent catalyst from a region of the pre-sintered polycrystalline diamond table so that the region is depleted of the metal-solvent catalyst to a maximum leach depth that is greater than about 250 μm as measured from the upper surface, a leach depth of the region decreasing with lateral distance from a central axis of the polycrystalline diamond table and toward the at least one peripheral surface.