Superhard constructions and methods of making same
A super hard polycrystalline construction comprises a body of polycrystalline super hard material, said body having an exposed working surface, a substrate attached to the body of polycrystalline super hard material along an interface and a plurality of apertures or channels. One or more of said apertures or channels extend(s) from the exposed working surface of the body into the substrate.
1. A super hard polycrystalline construction comprising:
a body of polycrystalline super hard material, said body having an exposed working surface, said body comprising inter-bonded super hard grains comprising natural and/or synthetic diamond grains, the super hard polycrystalline construction forming a polycrystalline diamond (PCD) construction;
a substrate attached to the body of polycrystalline super hard material along an interface; and
a plurality of apertures or channels, one or more of said apertures or channels extending from the exposed working surface of the body into the substrate; wherein:
the PCD construction further comprises a non-super hard phase comprising a binder phase located in interstitial spaces between the inter-bonded diamond grains.
2. The construction of claim 1 , wherein one or more of said plurality of apertures or channels are at least partly filled with a secondary material.
3. The construction of claim 2 , wherein the secondary material comprises one or more of a ceramic, a metal, an alloy or a refractory metal.
4. The construction of claim 2 , wherein the secondary material has a higher coefficient of thermal expansion than the bulk of the polycrystalline super hard material forming the body.
5. The construction of claim 1 , wherein a plurality of said apertures or channels have differing depths.
6. The construction of claim 1 , wherein the body has a peripheral outer surface extending between the working surface and the substrate, and wherein one or more of the plurality of apertures or channels closest to the peripheral outer surface have the greatest depth of the apertures or channels extending from the working surface into the substrate.
7. The super hard polycrystalline construction according to claim 1 , wherein a portion of the body of super hard material is free of a catalyst material for diamond, said portion forming a thermally stable region.
8. The super hard polycrystalline construction as claimed in claim 7 , wherein the thermally stable region comprises at most 2 weight percent of catalyst material for diamond.
9. The super hard polycrystalline construction of claim 1 , wherein a number of the apertures or channels extend through a portion of the body from the working surface and do not extend to the interface with the substrate.
10. The super hard polycrystalline construction of claim 1 , wherein a number of the apertures or channels extend from the working surface to the interface and/or extend through part of or through the entire substrate.
11. The super hard polycrystalline construction of claim 1 , wherein one or more of the apertures or channels comprises one or more of:
a circular cross-section;
a non-circular cross-section;
a curvilinear portion; and/or
a straight portion.
12. The super hard polycrystalline construction of claim 1 , wherein a number of the apertures or channels have a circular cross-section, and wherein the respective diameters of two or more of the number of the apertures or channels differ.
13. The super hard polycrystalline construction of claim 1 , wherein a number of the apertures or channels have a circular cross-section, and wherein the diameters of one or more of the apertures or channels closer to the peripheral edge of the body are less than the diameters of one or more of the apertures or channels closer to the longitudinal axis of the body.
14. The super hard polycrystalline construction of claim 1 , wherein the depth of the one or more apertures or channels from the working surface is greater than or equal to around 20 microns.
15. The super hard polycrystalline construction of claim 1 , wherein the depth(s) from the working surface of one or more of the apertures or channels closer to the peripheral edge of the body are greater than the depth(s) of one or more of the apertures or channels closer to the longitudinal axis of the body.
16. The super hard polycrystalline construction of claim 1 , wherein one or more of the apertures or channels extend in a plane inclined to the plane of the longitudinal axis of the construction.
17. The super hard polycrystalline construction of claim 1 , wherein one or more of said apertures or channels have a diameter of up to around 2 microns.