POLYCRYSTALLINE DIAMOND CUTTERS AND LIQUID SEDIMENTATION - HPHT METHOD OF MAKING THEREOF
Polycrystalline diamond cutters and methods of making thereof are described. The cutters include a substrate and a diamond body. The diamond body includes diamond particles spatially arranged according to a gradient of particle sizes. The methods include steps of suspending diamond particles in a liquid and allowing their sedimentation according to a gradient of particle sizes resulting in regions spatially arranged axially and/or radially in which a majority of diamond particles in one region have lower average sizes or average diameters comparative to a majority of diamond particles in a second region.
1 - 38 . (canceled)
39 . A method of making a polycrystalline diamond cutter, the method comprising:
forming a diamond particles feed layer by a process that includes i) making a temporary suspension of diamond particles in a liquid; ii) allowing sedimentation of the diamond particles; and iii) removing the liquid;
forming an assembly comprising, along the axis of symmetry of the assembly, a refractory container, the diamond particles feed layer, and a substrate; and
processing the assembly under high pressure high temperature sintering conditions (HPHT) from 5 GPa to 8 GPa and from 1300° C. to 1600° C. to sinter the diamond feed layer into a diamond body affixed to the substrate;
wherein a portion of the diamond feed layer comprises a plurality of diamond particles spatially arranged along a dimension of the layer according to a gradient of particle sizes.
40 . The method of claim 39 , wherein pouring includes contacting the suspension or the diamond particles with a baffle.
41 . The method of claim 40 , wherein the baffle directs a portion of the suspension of the diamond particles toward a peripheral region of the refractory container or to a central region of the refractory container.
42 . The method of claim 39 , wherein the process of forming the diamond feed layer further includes subjecting one or more of the temporary suspension and the sedimented diamond particles to a vibration.
43 . The method of claim 39 , wherein the liquid comprises an alcohol.
44 . The method of claim 39 , wherein the diamond feed layer comprises a plurality of diamond particles spatially arranged along the axis of symmetry or an axis parallel to the axis of symmetry according to a gradient of particle sizes, wherein the sizes increase in a direction toward the bottom of the refractory container.
45 . The method of claim 39 , wherein the diamond feed layer comprises a plurality of diamond particles spatially arranged along a radius originating at the axis of symmetry according to a gradient of particle sizes, wherein the sizes increase in a direction toward a peripheral region of the refractory container.
46 . The method of claim 39 , wherein the diamond feed layer comprises a plurality of diamond particles spatially arranged along a radius originating at the axis of symmetry according to a gradient of particle sizes, wherein the sizes decrease in a direction toward a peripheral region of the refractory container.
47 . The method of claim 39 , wherein the diamond feed layer is formed in the refractory container and the substrate is positioned over the layer.
48 . The method of any one of claim 39 , wherein the substrate is positioned in the refractory container and the diamond feed layer is formed over the substrate.
49 . The method of claim 39 , wherein the diamond feed layer, the substrate, or both, comprise a catalyst material.
50 . The method of claim 39 , wherein the diamond body comprises a plurality of bonded diamond crystals and a plurality of interstitial regions.
51 . The method of claim 1 , wherein a portion of the interstitial regions include a catalyst material or catalyst material sintering residue.
52 . The method of claim 1 , further comprising leaching a portion of the sintered diamond body to form interstitial regions substantially free of catalyst material or sintering residue thereof.
53 . A polycrystalline diamond cutter comprising a substrate and a diamond body including bonded diamond crystals and interstitial regions,
wherein the diamond body is attached to the substrate along an axis of symmetry,
wherein the diamond body includes a substrate interface side, and a working surface side axially separated from the substrate interface side, and
wherein a portion of the diamond body comprises a plurality of diamond particles spatially arranged along a dimension of the diamond body according to a gradient of particle sizes.
54 . The polycrystalline diamond cutter of claim 53 , wherein a portion of the diamond particles have an average diameter of 250 μm or less.
55 . The polycrystalline diamond cutter of claim 53 , wherein the diamond body comprises a plurality of diamond particles spatially arranged along the axis of symmetry or an axis parallel to the axis of symmetry according to a gradient of particle sizes, wherein the sizes increase or decreases in a direction from the substrate interface side toward the working surface side.
56 . The polycrystalline diamond cutter of claim 53 , wherein the diamond body comprises a plurality of diamond particles spatially arranged along a radius originating at the axis of symmetry according to a gradient of particle sizes, wherein the sizes increase or decrease in a direction from the axis of symmetry.
57 . The polycrystalline diamond cutter of claim 53 , wherein a portion of the interstitial regions include a catalyst material or catalyst material sintering residue.
58 . The polycrystalline diamond cutter of claim 53 , wherein a portion of the interstitial regions are substantially free of catalyst material or catalyst material sintering residue.
59 . The polycrystalline diamond cutter of claim 53 , wherein the portion of the diamond body comprising interstitial regions substantially free of catalyst material or catalyst material sintering residue, extends from the working surface side into an interior volume of the diamond body.