Thermally stable pointed diamond with increased impact resistance
View Patent ↗An insert comprises a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate. The diamond body comprises a substantially conical shape with conical side wall terminating at an apex. The diamond body comprises a first region with a metallic catalyst dispersed through interstices between the diamond grains and a second region proximate the apex with the characteristic of higher thermal stability than the first region.
1. An insert, comprising:
a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate, the sintered polycrystalline diamond body including:
an apex;
a substantially conical shape and a conical side wall terminating at the apex;
a first region between the cemented metal carbide substrate and the apex, the first region comprising a first characteristic thermal stability; and,
a second region covered by a layer of the first region, the second region including:
a natural diamond; and,
a second characteristic thermal stability higher than the first characteristic thermal stability.
2. The insert of claim 1 , wherein the natural diamond forms the apex.
3. The insert of claim 1 , wherein a thickness of the layer of the first region that covers the second region is less than a thickness of the first region.
4. The insert of claim 1 , wherein the second region comprises at least one of a sintered natural diamond, a single crystal natural diamond, coarse saw grade diamond, cubic boron nitride, a non-metallic catalyst, and a single crystal synthetic diamond.
5. The insert of claim 1 , wherein the sintered polycrystalline diamond body is thicker than the cemented metal carbide substrate.
6. The insert of claim 1 , wherein the first region separates the second region from the cemented metal carbide substrate.
7. The insert of claim 1 , wherein the second region is substantially free of a metallic catalyst.
8. The insert of claim 1 , wherein first region and the second regions are joined at a non-planar interface.
9. A bit, comprising:
an insert having a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate, the sintered polycrystalline diamond body including:
an apex;
a substantially conical shape and a conical side wall terminating at the apex;
a first region between the cemented metal carbide substrate and the apex, the first region having a metallic catalyst dispersed through interstices between diamond grains that form the polycrystalline diamond, the first region comprising a first characteristic thermal stability; and,
a second region covered by a layer of the first region, the second region including:
a natural diamond; and,
a second characteristic thermal stability higher than the first characteristic thermal stability.
10. The bit of claim 9 , wherein the bit is at least one of a drill bit, a drag bit, a roller cone bit, and a percussion bit.
11. The bit of claim 9 , wherein the insert is at least one of a milling pick, a mining pick, pick, an excavation pick, and a trenching pick.