Polycrystalline diamond constructions

Patent metadata

Field	Value
Publication number	US-2019160536-A1
Application number	US-201716309470-A
Country	US
Kind code	A1
Filing date	Jun 26, 2017
Priority date	Jun 28, 2016
Publication date	May 30, 2019
Grant date	—

Abstract

Polycrystalline diamond constructions are formed from a mixture of diamond grains including a first volume of fine-sized diamond grains, and a second volume of coarse-sized diamond grains. The fine-sized diamond grains are partially graphitized, and the coarse-sized diamond grains are not graphitized. The mixture of diamond grains is subjected to high pressure/high temperature sintering process conditions in the presence of a sintering aid thereby forming polycrystalline diamond. Contact areas between coarse-sized diamond grains in the polycrystalline diamond construction are substantially free of graphite.

First claim

What is claimed is:

1 . A diamond grain composition for sintering polycrystalline diamond constructions comprising:
a first volume of fine-sized diamond grains having an average grain size of from about 0.01 to 6 micrometers, wherein the fine-sized diamond grains are partially graphitized; and a second volume of coarse-sized diamond grains having an average grain size of greater than 6 micrometers, wherein the coarse-sized diamond grains are not graphitized.

2 . The diamond grain composition as recited in claim 1 wherein the mixture further comprises a sintering aid.

3 . The diamond grain composition as recited in claim 2 wherein a population of the sintering aid is fused together with the partially graphitized fine-sized diamond grains.

4 . The diamond grain composition as recited in claim 2 wherein the sintering aid is selected from the group consisting of iron, cobalt, nickel, manganese, and combinations thereof.

5 . The diamond grain composition as recited in claim 1 wherein the composition comprises about 2 to 50 percent by volume of the fine-sized diamond grains based on the total volume of the first and second volumes of diamond grains.

6 . The diamond grain composition as recited in claim 1 wherein the composition comprises a minority volume content of the fine-sized diamond grains, and a majority content of the coarse-sized diamond grains based on the total volume of the first and second volumes of diamond grains.

7 . A polycrystalline diamond construction formed by subjecting the diamond grains composition of claim 1 to high pressure/high temperature sintering process conditions in the presence of a sintering aid, wherein contact areas between coarse-sized diamond grains in the polycrystalline diamond construction are substantially free of graphite.

8 . The polycrystalline diamond construction as recited in claim 7 wherein the contact areas between the coarse-sized diamond grains are substantially free of graphite.

9 . A polycrystalline diamond construction comprising:
a polycrystalline diamond body comprising bonded-together diamond grains, wherein the bonded-together diamond grains comprise coarse-sized diamond grains that are mostly bonded together with one another and fine-sized diamond grains mostly interposed within interstitial regions existing between the bonded-together coarse-sized diamond grains, wherein the fine-sized diamond grains used to form the construction are partially graphitized before sintering, and wherein contact areas between the coarse-sized diamond grains are substantially free of graphite.

10 . The polycrystalline diamond construction as recited in claim 9 wherein the interstitial regions further comprise a sintering aid.

11 . The polycrystalline diamond construction as recited in claim 9 wherein the polycrystalline diamond body comprises from about 2 to 50 percent by volume fine-sized diamond grains based on the total volume of the fine- and coarse-sized diamond grains.

12 . The polycrystalline diamond construction as recited in claim 9 wherein the fine-sized diamond grains have an average particle size of between about 0.1 to 6 micrometers, and wherein the diamond coarse-sized diamond grain have an average particle size of greater than 8 micrometers.

13 . A bit for drilling subterranean formations comprising a body and a number of cutting elements operatively connected with the body, wherein the cutting elements comprise the polycrystalline diamond construction as recited in claim 9 , and wherein a metallic substrate is jointed together with the diamond body.

14 . A method for making a polycrystalline diamond construction comprising:
combining a volume of fine-sized diamond grains with a sintering aid; subjecting the volume of fine-sized diamond grains and sintering aid to conditions suitable for partially graphitizing the fine-sized diamond grains; combining the partially graphitized fine-sized diamond grains with coarse-sized diamond grains that are substantially free of graphite to form a mixture; and subjecting the mixture to high pressure/high temperature process conditions to sinter the diamond grains to form polycrystalline diamond.

15 . The method as recited in claim 14 wherein during combining the volume of fine-sized diamond grains with the sintering aid, the sintering aid material is in the form of grains mixed together with the fine-sized diamond grains.

16 . The method as recited in claim 14 wherein combining the volume of fine-sized diamond grains with the sintering aid comprises providing the sintering aid as a coating on an outside surface of the fine-sized diamond grains.

17 . The method as recited in claim 14 wherein subjecting the volume of fine-sized diamond grains to graphitization conditions comprises exposing the fine-sized diamond grains to an elevated temperature of from about 700 to 1,400° C.

18 . The method as recited in claim 14 wherein the fine-sized diamond grains have an average particle size of from about 0.01 to 6 microns, and the sintering aid material has an average grain size that is the same or less than the fine-sized diamond grains.

19 . The method as recited in claim 14 further comprising placing the mixture adjacent to a metallic substrate prior to subjecting to high pressure/high temperature process conditions to join the polycrystalline diamond to the substrate.

20 . The method as recited in claim 14 wherein the polycrystalline diamond construction comprises mostly bonded together coarse-sized diamond grains, and wherein contact areas between the bonded together coarse-sized diamond grains are substantially free of graphite.

Assignees

• Smith International

Inventors

• Voronin Georgiy

Classifications

• B22F3/1007 Primary

  Atmosphere (B22F3/1021 takes precedence) · CPC title

• B22F2005/001

  Cutting tools, earth boring or grinding tool other than table ware · CPC title

• B01J3/062

  characterised by the composition of the materials to be processed · CPC title

• B22F1/12

  Metallic powder containing non-metallic particles (containing lubricating or binding agents or organic material B22F1/10) · CPC title

• C22C26/00 Primary

  Alloys containing diamond {or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes} · CPC title