Double Sintered Thermally Stable Polycrystalline Diamond Cutting Elements
Embodiments of the invention include a polycrystalline diamond compact comprising a plurality of double-sintered polycrystalline diamond segments. The polycrystalline diamond segments are configured to remain thermally stable at a first temperature. The polycrystalline diamond segments are positioned upon and bonded to a transition layer of single-sintered polycrystalline diamond that is configured to remain thermally stable at a second temperature lower than the first temperature. The transition layer is positioned upon and bonded to a substrate. Embodiments of the invention have improved thermally stability, resulting in fewer defects during manufacturing and improved longevity in use.
1 . A polycrystalline diamond compact comprising:
a first layer, said first layer including a plurality of polycrystalline diamond segments positioned thereupon; said plurality of polycrystalline diamond segments being separated by an interfacial boundary formed of an abrasive material;
a second layer, said first layer being bonded to a second layer, said second layer being formed in part from said abrasive material; and,
a substrate, said second layer being positioned upon and bonded to said substrate.
2 . The compact of claim 1 , wherein said polycrystalline diamond segments have a granular structure comprised of polycrystalline diamond grains and interstices, said interstices being substantially free of a catalytic material.
3 . The compact of claim 2 , wherein said interstices include a non-catalytic material.
4 . The compact of claim 3 , wherein said non-catalytic material is a non-metallic material.
5 . The compact of claim 1 , wherein said polycrystalline diamond segments have a granular structure comprised substantially of polycrystalline diamond grains and substantially free of interstices.
6 . The compact of claim 1 , wherein said abrasive material comprises a granular structure comprised of polycrystalline diamond grains and a catalyst.
7 . The compact of claim 1 , wherein the second layer further comprises a substantially conical surface.
8 . The compact of claim 1 , wherein said first layer is configured to remain thermally stable at a first temperature and said second layer is configured to remain thermally stable at a second temperature lower than said first temperature.
9 . A polycrystalline diamond compact comprising:
a plurality of double-sintered polycrystalline diamond segments, said diamond segments configured to remain thermally stable at a first temperature;
a transition layer of single-sintered polycrystalline diamond configured to remain thermally stable at a second temperature lower than said first temperature, said polycrystalline diamond segments positioned upon and bonded to said transition layer; and,
a substrate, said transition layer positioned upon and bonded to said substrate.
10 . The compact of claim 9 , wherein said polycrystalline diamond segments have a granular structure comprised of polycrystalline diamond grains and interstices, said interstices being substantially free of a catalytic material.
11 . The compact of claim 10 , wherein said interstices include a non-catalytic material.
12 . The compact of claim 11 , wherein said non-catalytic material is a non-metallic material.
13 . The compact of claim 9 , wherein said polycrystalline diamond segments have a granular structure comprised substantially of polycrystalline diamond grains and substantially free of interstices.
14 . The compact of claim 9 , wherein said transition layer comprises a granular structure comprised of polycrystalline diamond grains and a catalyst.
15 . The compact of claim 9 , wherein the transition layer further comprises a substantially conical surface.
16 . A method of forming a polycrystalline diamond compact comprising:
providing a canister configured to receive a plurality of sintered polycrystalline diamond segments and an unsintered abrasive powder;
filling said canister with said unsintered abrasive powder;
positioning said plurality of polycrystalline diamond segments upon said unsintered abrasive powder, an interfacial boundary formed of said unsintered abrasive powder separating each of said plurality of polycrystalline diamond segments; and
applying a temperature and a pressure to said canister to sinter said unsintered abrasive powder and bond said polycrystalline diamond segments to said sintered abrasive powder.
17 . The method of claim 16 , further comprising positioning a substrate in said canister, said unsintered abrasive powder being positioned between said substrate and said sintered polycrystalline diamond segments.
18 . The method of claim 16 , further comprising:
providing another canister configured to receive at least a first disc, said first disc including at least one rib on a front surface of said first disc;
filling said canister with at least diamond powder;
placing said first disc in said canister such that said front surface of said first disc is in contact with said diamond powder; and,
applying a temperature and a pressure to said canister to sinter said diamond powder to form said sintered polycrystalline diamond segments.
19 . The method of claim 18 , further comprising:
removing said sintered polycrystalline diamond segments from said another canister;
processing said polycrystalline diamond segments to make said polycrystalline diamond segments more thermally stable than unprocessed polycrystalline diamond segments.