Cutting tables including rhenium-containing structures, and related cutting elements, earth-boring tools, and methods

1. A cutting table, comprising:

a polycrystalline hard material; and

at least one rhenium-containing structure embedded within and completely surrounded by the polycrystalline hard material and comprising greater than or equal to about 10 weight percent rhenium, the at least one rhenium-containing structure longitudinally offset from upper and lower longitudinal boundaries of the polycrystalline hard material.

2. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises at least one rhenium-containing alloy comprising rhenium and at least one refractory metal.

3. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises a single, substantially continuous elongate structure.

4. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises a group of relatively smaller, discrete structures positioned proximate one another to form a relatively larger, elongate structure substantially free of bonds directly coupling the relatively smaller, discrete structures to one another.

5. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises a plurality of rhenium-containing structures extending in one or more substantially non-linear paths within the hard material.

6. The cutting table of claim 5 , wherein the plurality of rhenium-containing structures comprises multiple rhenium-containing structures substantially aligned with one another along a single radial position.

7. The cutting table of claim 5 , wherein the plurality of rhenium-containing structures comprises:

at least one first rhenium-containing structure extending in a first non-linear path; and

at least one second rhenium-containing structure laterally offset from the at least one first rhenium-containing structure and extending in a second non-linear path.

8. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises a single rhenium-containing structure extending substantially continuously in an arcuate path within the hard material.

9. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises a plurality of rhenium-containing structures extending in one or more substantially linear paths within the hard material.

10. The cutting table of claim 1 , wherein the at least one rhenium-containing structure comprises:

at least one first rhenium-containing structure extending in a non-linear path within the hard material; and

at least one second rhenium-containing structure extending in a substantially linear path within the hard material.

11. The cutting table of claim 1 , wherein the at least one rhenium-containing structure is oriented non-perpendicular to an upper longitudinal boundary of the hard material.

12. The cutting table of claim 1 , wherein the polycrystalline hard material comprises a polycrystalline material including at least two regions having one or more of different average grain sizes and different grain size distributions than one another.

13. The cutting table of claim 1 , wherein the polycrystalline hard material exhibits inter-bonded hard material particles and interstitial spaces between the inter-bonded hard material particles, at least some regions of the polycrystalline hard material substantially free of catalyst material within the interstitial spaces thereof.

14. The cutting table of claim 1 , further comprising at least one perforation longitudinally extending into the hard material and longitudinally overlying the at least one rhenium-containing structure.

15. A cutting element, comprising: a supporting substrate; and a cutting table over the supporting substrate and comprising: a polycrystalline hard material; and at least one rhenium-containing structure comprising greater than or equal to about 10 weight percent rhenium embedded within and completely surrounded by the polycrystalline hard material the at least one rhenium-containing structure longitudinally offset from upper and lower longitudinal boundaries of the polycrystalline hard material.

16. An earth-boring tool comprising the cutting element of claim 15 .

17. A method of forming a cutting element, comprising:

providing at least one rhenium-containing structure comprising greater than or equal to about 10 weight percent rhenium within a hard material powder comprising discrete hard material particles, the at least one rhenium-containing structure embedded in and completely surrounded by the hard material powder;

providing a supporting substrate adjacent to the hard material powder; and

subjecting the supporting substrate, the at least one rhenium-containing structure, and the hard material powder to elevated temperatures and elevated pressures to inter-bond the discrete hard material particles of the hard material powder and form a cutting table attached to the supporting substrate, the cutting table comprising a polycrystalline hard material and the at least one rhenium-containing structure embedded within and completely surrounded by the polycrystalline hard material such that the at least one rhenium-containing structure is longitudinally offset from upper and lower longitudinal boundaries of the polycrystalline hard material.

18. A cutting element, comprising:

a supporting substrate; and

the cutting table of claim 1 attached to the supporting substrate.