Polycrystalline diamond constructions
AssigneeSmith International, Inc.
InventorGeorgiy VORONIN
Life of this patent
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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.
Claims20
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.
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.
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.
Dependencies are inferred from the claim text.